Just got my shiny new N800 and couldn't be happier with my purchase. OS2007 was a good start, but flash videos were unwatchably slow and Opera didn't work right on a lot of Web2.0 sites (Facebook comes to mind). I made the leap to OS2008 and haven't looked back; the browser has yet to not work on a site, it's only crashed on me once (with a ton of other things open) and the system is very noticeably faster (being clocked to 400MHz and all). Skype crashes consistantly ~10 seconds into a call, but I only know 1 person that uses Skype so I don't much care. Personally, not having the couple applications ported to OS2008 is an acceptable compromise for a much better experience. I also just installed scratchbox and the Maemo SDK and I'd like to tinker around with custom kernels and maybe even some applications.

One problem I consistently have is is the pdflush process eating 100% of the CPU and locking up the system. I don't know if it's a fluke thing (I did a restore from OS2007) or if this is common. I'd like to play with booting off MMC too as I expect it will run much faster without the compressed filesystem. I also get MUCH higher read/write speeds to the SD cards as it is.

Anyway, that's my 2 cents. Sorry to ramble on, I just love this thing and I'm sure glad I bought it. Back on topic, if you haven't tried OS2008 yet, I highly recommend it. If you can't afford to wait for a specific application though, it's probably worth waiting to upgrade.

EDIT: My flash worked flawlessly the first try too. I'm running Linux on my desktop already, so maybe that helped. I have no experience flashing with windows and I'm sure I never will.