2007 isn't _that_ old really. If refrigerated it is probably fine but I know most shops around here that used to refrigerate slide film now have it sitting on the counter for cheap and my experience with Velvia kept on the counter is that it comes out like crap unfortunately with a magenta cast that makes it useless for projection.

Must it be slides? Can you not pick up a few rolls of Fuji or Kodak C-41 film or something like that at the drug store? Might be better safe than sorry for an important trip even if it means not shooting slides.