Well, Portals & Planes, Blood & Fists, Classic Play: Book of Dragons, and Draconomicon are just a little over a year old.
But since then, the books I have found most interesting and useful include:
1) Expanded Psionics Handbook
2) Beyond Countless Doorways
3) Classic Play: Book of the Planes
4) Advanced Bestiary
5) World's Largest Dungeon
Looking forward to:
1) Codex Anethema
2) I'll cop Rappan Athuk Reloaded
3) Complete Adventurer (cautiously)
4) Legend of the Samurai
That's all I got. Publishers are playing things closer to the vest these days, and there is very little that I see is coming out that I just feel I have to add to my game.