Pros: Price Point, stability, user interface
Cons: System Requirements, won't work with older peripherals, long install time if upgrading from xp
If you didn't pre-order, wait until installation issues have been solved for upgrades from XP. Mine took a 6 hour phone conversation with tech support in India because it hung up on the "starting windows" screen-for two hours. Turns out the OS was trying to write onto my 3GB of RAM instead of my hard disk. I had to remove all but 1 GB. My older graphics card caused additional hangs, but the Windows 7 compatability checker didn't tell me I could solve these with an update of the intel chipset beforehand. All it said was I wouldn't be able to use aero. 32 bit version still won't read more than 4 GB of RAM. I don't know if that is physically impossible or just an oversight.
If you have Vista and use the web-filter, don't switch if the want to continue using it. 7 has no-built in filter and doesn't link to any free imports. Instead it uses an IE based filter. I'm not sure if that even works if you use Mozilla or Opera.
My older HP all-in one psc2210 doesn't have a driver that works with windows 7. Check their website beforehand. I really miss that HP software and the new stuff that works through windows live doesn't let me move photos around on a page and/or adjust sizes before printing. It only offers standard print sizes.
With that said, the system is very stable once you get it up and running. Sound and graphics card errors were stashed under the white flag and didn't cause shut-downs, and the links to solutions worked to resolve both. Streamlined look with easier accessibility yet not so different as to cause confusion.