Yes and No.
No official updates per se, but, one rules system (weapon sizes) got re-done in 3.5 and is different.
Wizards of the Coast's general policy, though, is that they are updating 3.0 items that need it in the order of most problematic first. The stuff in the Arms & Equipment Guide should mostly not need to be updated, so should be usable "as is" in most campaigns.