Sienna Guillory's cameo in Resident Evil: Afterlife came at the tail end of the movie, and was obviously supposed to be a surprise that was ruined when a blurry photo that revealed Guillory and eventually forced Milla Jovovich to admit that Guillory would return as Valentine.
RE:5 alert! Training begins! I aim to mostly put less in the big hole on the front of my face than comes out of the little one on my arse.
No word yet on director, Paul W.S. Anderson's inevitable involvement, or if Jovovich will be back, but Sony has set a release date of September 14, 2012.