This is a squirrely sort of question, for a few reasons:
- Text fields can be "dynamic" without relying on "external resources,"
- The post is six months old, and
- The Flash search-player project is under active development.
So it'd be difficult to get a solid answer from anyone who isn't either a Google or Adobe engineer working on the search-player project, and even then, it's still a somewhat complicated one, depending on the implementation. So the safest and most dependable answer, right now anyway, is probably Maybe -- but I wouldn't necessarily count on it, yet.
Still, that said, the entire purpose of the search-player project is to solve exactly this kind of problem, so while that answer might not necessarily be yes today (which it might be, only we don't know know for sure), it'll definitely edge closer to yes with time.
One thing you can do now is watch this video in which Jim Corbett (from the Flash-player team and who's been working with Google directly) explains all this stuff in about as much detail as you're likely to get from anyone today. (At about 19 minutes in, he live-demos the virtual-user indexing/text-field stuff at work, too.) It should give you a pretty clear picture of things as they stand now, where they're headed, what works and what doesn't, etc., so you can weigh the options and make a good decision for your project. Good luck!