Thanks for the link. Yes, neonicotinoids are bad for bees, but so are lots of other things. Other than one special symptomatic consistency (aside from death), there still doesn't appear to be an especially good reason to peg most of the blame on them yet. Doesn't mean they aren't to blame in a large measure, but it doesn't appear there is any reason to think that YET. It's one of those annoying "more study is needed" situations. Several original hypothesises as to the cause of CCD have been ruled out by more study, but none confirmed yet.

The linked wikipedia article says neonicotinoids' role is being studied as a cause if CCD, perhaps in combo with other factors, but doesn't draw a clear line from one to the other. However, it does, as the parent post mentions, provide some nice references for more info.