In keeping with the tradition of this:
I wanted to present this thread. Here are the two biggest questions AFTER people update:
1) Where is SetCPU, I don't see it? Download it from the market for $0.99
2) Something is not working with SetCPU, why is the ROM listed as X mhz but this only shows X mhz? Because you need to go to SetCPU settings, device selection, scroll all the way down and choose auto detect (do NOT choose 'Droid'). Now you can overclock with SetCPU. Also, if you are not rooted AND using a ROM that supports overclocking (Sholes, Bugless Beast, etc), you will not be able to overclock.
3) If I want to upgrade from X rom to X newer rom, will it remove all of my programs, contacts, shortcuts, settings, etc? Yes and no. It will NOT remove those things IF you use the update.zip method of installing the new ROM. If you use the Nandroid Backup method, it could indeed cause you to lose everything and have to re-install (depending on how you do it). You can however download a backup program from the Market to simplify the re-installation process.
4) If you want to update your ROM in the future using update.zip, all you need to do is boot into SPRecovery again using the X/power button method, and choose install > allow update.zip installation > install /sdcard/update.zip (deprecated) > hit the power button > reboot system
5) If you want to go back to original theme (not smoked) simply go here and the third link down is Stock Theme Patcher (credit to Pete) which will get you back to stock.