I'm not going into what WinFS is and what it isn't, but you bring the point about access times. I don't think WinFS search performance will help (or relate to) rapid random accesses scenarios where you have more or less static access pattern to hundreds
of files (Like loading Visual Studio).
It's hard to tell whether we have faster access times in future mainstream mass storage systems. The history of HDD does not show big improvements in mainstream IDE drive access times and it's hard to say will HDD technology change to something else in near
future, not likely in a few years.
What I do hope is that someone comes up with some background access optimizer service which looks how applications access data when starting up and then arranges and defragments the files with the access pattern data in mind.
I definetely agree that NTFS should be gone in Longhorn but that seems a bit unlikely at this point. If they are going to keep NTFS, a service which I described above could help, though a few problems come in mind regarding how it could be implemented.