However, it doesn't seem to be on the release schedules - at least, not the PC version anyway. Amazon.co.uk has the Xbox version, but no listing for the PC. Given it's been released in the US since April, this seems odd...
Update - reply from Amazon:
At the moment we do not have any plans to release the PC version of “Psychonauts”. However this may change in future and we would advise you to keep checking on the website.
Update 2 - from Majesco (the publisher), who seemed unconcerned:
The game is very big and will take some time to localize so it will be awhile before it hits your area (and when it does it will be on Xbox, PS2 and PC). It probably won't be sooner than fourth quarter but that's still to be determined. We'll keep you updated as it comes
together.
I mused on why they needed to localise a game in English for the UK...
It's being localized for several territories and must launch at the same time. PC will be included but as I said, it will be a long time. You could always order the US version from a US retailer and have them ship it to you though. EBGames.com and GameStop.com both sell it. DoubleFine.com does too.
I ended up ordering from Doublefine (since they're the developer) - even with the £ dropping a touch, it's only £27 including shipping.
Yeah, saw a special on this on G4TV and it looked really cool. Was gonna pick it up for Xbox but 50 bucks is a bit much for a game like this. So, I'll wait til it comes down some.