Noel finished the last song (In the Heat of the Moment) the day after the World Cup final. They couldn't release it in Ocotber because the MG reissue was still selling copies. And for some reason Noel only can release an album in October or March.

"Some reason" is simple: those are the two time frames when albums sell the most. March you got the whole festival season ahead (new listeners), and October is perfect for Christmas (gift shopping).

It's not hard to understand people : Noel WONT release his record if Liam is still actively touring coz that would cannibalize both acts. It would be like releasing a superman and a batman movie at the same time.

So if Liam release his album in june/july and tours until october, no Noel this year. If he only does festival until august, there is a slight chance for october.

My money (that i dont have) for march next year.

I really wonder if Noel will play his new single at the Joshua Tree tour.

The basic answer comes down to the changes that can be made.

The producer mostly deals in a blank state. He/she work with the artist on a number of demos and begin to record actual version. They're actually within the recording process, and can sometimes contribute compositions. The producer's job, is when finished, to have fully realized the artist's vision in recorded form.

The mixing engineer then receives what producer and artist have thought up (sometimes the producer will also act as the mixing engineer, sometimes someone separately will be hired). When you record, some instruments are naturally louder or softer, take up more head room or less. The mixing engineer's job is to make everything in the recording have clarity, and to make sure that certain sections resonate well. Like, you may have piano playing throughout the entire song, but the mixing engineer makes sure that you really hear it in the chorus, when an extra kick might be needed. So he'll bring the levels for it up in the chorus.

The mastering engineer receives what is essentially the final product. When songs are recorded, typically they have not been sequenced as one full album (that is with fade-ins and out's between each song is added). They're usually not recorded at the same level either. Songs whose volumes shift drastically from one song to the next. You don't mind some change, but you want it to sound like an album, so you want the lowest low in volume, and the highest high, to match from song to song. You also want to make sure that the album plays well, no matter the device or platform, whether CD, mp3, vinyl, and radio. All those platforms can shift balance of a song, bringing out unintended noises and sounds. In the end, the mastering engineer's job is to make sure that the final album has consistency and balance.

The more advance the album is in the process, the less there are whole sale changes. In the recording process with the producer, anything is possible. When it gets to mixing, recording mostly stops. The only recording that might happen is if in the mixing there appears to be a mistake in the recording (such as an off tempo or sour note), because sometimes mistakes get hidden by other instruments. In that case, that instrument will be re-recorded. But that's the extent of the recording. 99.9% of the time you're not adding a completely new instrument track while mixing. Like if there wasn't a piano on the original track, you can't decide while mixing that you want a piano on there now (you could, but you can't), you'd have to re-do the mix for the song. You work with and sometimes edit and re-do what is already present in the track. When mastering happens, all changes cease. The mastering engineer isn't doing recording sessions nor is the mastering engineer re-doing the mix. Those things are set in stone by the time it get to him/her. There are extremely rare occasions where the mastering engineer will notice something that was missed, and it will be sent back for mixing, but in today's studios, that's incredibly rare. Most of the time, if it gets to a mastering stage, it's a 99.9% chance that it'll be released.

Lastly, each step takes less and less time. Recording can be months or years. Mixing can be weeks or months, and mastering is usually days or weeks. And some times, depending on the artist, the artist will have less and less of a role. The artist is 100% contributing to recording. Artist participation in mixing can fluctuate from 0-100%. Some artists don't handle nor care about the mixing, some really do. But most of the time, the mixing engineer will do the first mix themselves, without the artist. If the artist wants to participate, then they'll come in for next couple rounds, for input. Mastering rarely has artist participation, which is surprising that Noel would care But maybe he just wanted to be there to go through the possible treatments himself and decide, which can save time rather than having a back and forth). The mastering engineer will typically work alone. They'll listen to the album, ask the artist what they're looking for dynamically, and pick 3-4 mastering treatments that fulfill what the artist wants. They'll then send artist samples of each song using each treatment, and let the artist decide which one they like more. Once a decision is given, then the mastering engineer will master the entire album using that treatment, then send it to the artist for final approval. If the artist doesn't like it, then it gets re-mastered.

I really wonder if Noel will play his new single at the Joshua Tree tour.

Doubtful.

There's no guarantee loads of U2 fans filling 80,000-seater stadiums will be into NG's stuff enough to not have it go flat with an unheard song. 

He'll play 10-12 songs, and it'll be the usual Oasis classics plus the most popular of his own I'd imagine. Maybe a throwaway tune thrown in there too.

I'd wager

1. Everybody's On The Run
2. Heat of the Moment
3. Lock All The Doors
4. If I Had A Gun...
5. You Know We Can't Go Back
6. Champagne Supernova
7. Half The World Away
8. Digsy's Dinner
9. AKA... What A Life!
10. The Masterplan
11. DLBIA

I'd love to be wrong and for him to play a load of rarities, but can't see it.

I'll guess 5 HFB tunes and 5 Oasis tunes. He didn't play any Chasing Yesterday songs at the Teenage Cancer Trust did he? I didn't bother going to any of his Chasing Yesterday gigs, but hearing them live, I get the impression they didn't work quite as well as ones from his debut album?

Sounded fine both times I went to see him. Especially In The Heat Of The Moment and The Mexican, perhaps the two lesser songs on CY, worked very well.
The Dying Of The Light was a bit of a snoozefest and Riverman was a bit of a downer though.