Open Source & Embedded
... because it was never as big and bloated as the Internet bubble. Furthermore, unlike all those Internet services and software packages that have just disappeared without a trace, open source software stays around: the investment in it isn't lost.
Of course, I do have my doubts that a company like Red Hat makes sense. Open source is best for specialized, highly-skilled consultants and professionals. It also makes sense for a few hardware vendors and large, established consulting shops like IBM. But companies like Red Hat and VA Linux aren't in that league.