You need to do your research on Y2K. The US alone, between government and private sector spent over 100 billion on solving the Y2K issue. The Fortune 100 company I'd worked for spent about 500 million. I can assure you that there were still glitches at those companies.
Quite a few of the "solutions" were simply designed to push back the problem, as well.
I know of one system in particular, which is used globally that was just patched; not truly fixed. The patches are only good until 2020. After that if a replacement isn't done, all bets are off. It's 2012 ... and there's no replacement in sight yet.
People seem to think that just because nothing significant "broke" that it was all hype and a non-issue. Having worked half of the 90's on patches for the event, I know for a fact it WAS an issue. It took a global effort by millions of folks ranging from hardware designers, firmware designers, OS teams, driver programmers, and software engineers in a variety of fields, to actually make it through in one piece.
Anyway, some stuff was just a stopgap, and the problem is, the clock on those stopgaps is still running. A new generation of folks is coming up at the helm, and many with new priorities. A lot of "losttech" is floating around out there. Abandoned by the new generation that (incorrectly) assumed that obsolete systems would be replaced.
Then again, they didn't know what an impact or shift our economy would face in 2001. Or how so many US programming companies would get emptied in favor of off-shore development, were quality control and communications issues left a massive deficit in capability and knowledge base.
It all hangs by a thread. It really, truly does.