Well also the fact that Sega are actually fairly clued up when it comes to pricing. The original All Stars released at £20 too, so it wouldn't be unreasonable. I would like to see a price reduction for waiting, but it's unlikely.
Ahem. Also, I can't wait for any assets to be ripped and to be used for Generations levels. Unless they already took them from it to start with.
I'm going to go with £20. So, I saw at GMG that the game is £20, but has a 10% discount. On top of that, until the 18th of Jan, you can use a discount code (on the front page) to get a further 20% off. By the end, I was able to pay £13.50. I haven't gone for it...yet, but it might be worth investigating. According to GMG too, its release date is the 31st of Jan, which is a Thursday.
Oh, also, the Steam registry suggests a 4-pack, so it might be worth investigating that. I don't want to miss out on getting the GMG deal though as it seems particularly great. We'll see what happens in the mean time.
EDIT THE SECOND:
It's now up on Steam. £20, with a 10% pre-order bonus. 4-pack is £53, making it £13.25. Given the price difference between it and GMG being fairly negligible, I'll happily go in if other people are interested.
And release date is confirmed 31st Jan.