Benefits do sound nice, but...
I'm not really into plugging in my flash drive to use as extra memory/cache. Seems like such a band-aid and it's strange. I'm also not into creating a memory "hard drive" and plugging it into a PCI-E slot. Again, band-aid. I'll just use a nice HDD with a good amount of cache and 2 GB of decently fast memory and accept it as it comes.
I'll probably never use widgets.
The new UI is nice but I've realized I get used to those things pretty quickly.
I never search for things since I know where they are.
I don't use Task Scheduler, as my AV program schedules itself, I don't think drives need defragged much nowadays, and system restore points are created automatically.
I don't need Windows Backup at all. All one needs for backup is a good synchronization program, and I doubt Windows Backup's sync features match those of my current software, ViceVersa.
In short, Vista does offer a lot of good improvements, but I'm not interested at all in the "band-aid" features, and I'm in no hurry to get it. I'll probably make the switch when my university gives out the discs for free like they currently do with XP and Mac OS X.