The difference this time around is that:
1: People started worrying about profitability years ago and are actually trying to make it happen
2: There are quite a few tech giants and hundreds of smaller tech companies with stable income sources
Remember that in '99 Microsoft hadn't launched XP, Google was years away from an IPO, and cell phones were still a luxury.
I think there are little bubbles here and there, but the pop won't be as devastating.