I found this information on Sony's Threespeech Blog:

The Resident Evil: Extinction Blu-ray disc, released on 2nd January in the US, will contain demo versions of Resident Evil 5 and Devil May Cry 4. Also featured are plenty of Profile 1.1 features including picture in picture commentary, and Blu-Wizard 2.0 which enhances interactive menu features such as organisation.

Tech specs for the disc are the usual 1080p AVC-MPEG4 video transfer as well as an uncompressed 5.1 audio track. Extinction will also be released as part of a trilogy set including the original first Resident Evil film on the same date.

No word on a UK release date yet – we’ll keep you posted.

I've also read that the regular DVD version of the movie will also contain the demos, presumably playable on the 360. Not like I needed another reason to buy this movie, as my love for zombies and Resident Evil games is fairly well known, but it's nice to see that I'll get a chance to play these games relatively soon.

UPDATE - Capcom has now announced that these are just videos, not demos. I will keep you posted if this changes.