I just beat the game, and I have to say that while it is definitely a fun game and worth playing, I think it's time we retire the RE storyline. The game explains a number of things about Wesker and Umbrella, but then has a stupid ending leaving you thinking, "Now what!?" I strongly suspect that the next game will be based off of Ada Wong's actions in RE4, which likely means Capcom won't change much in the next game.
RE5 seems like a good candidate for episodic DLC, since Umbrella has all these different branches and there's apparently 10 versions of this stupid virus being developed everywhere it would be good to just use the base RE5 engine (with a fixed inventory system first though) and add on episodes, as opposed to whole new games that take 2+ years of development.
Overall I had fun with the game. I'm sure it would have been more fun with a human companion instead of AI, but it wasn't that bad. Yes, her stupidity did result in a few unnecessary "Your Partner Died" screens, but with the right weapons she was rather useful.
A few complaints:
1. Inventory System item exchanges
2. Random quicktime events that at times felt like playing old Sega CD games like TimeGal and Dragon's Lair
3. Crazy plot
Overall, an 8 out of 10 (I gave RE4 a 10 out of 10.)