here are the instructions from ACD168.. all credit goes to him for this info.
INSTRUCTIONS GETTING TO UP-TO-DATE 2.1 1.22.605.2
1) download the last 2.1 RUU from here -
Index of /shipped/Incredible
2) open the RUU, don't use it though, just open it
3) go to start menu, search programs and files, and type "
%TEMP%"
4) Now You'll see a bunch of folders that are named like this "{6D62E500-13A0-40F7-966B-A84B121949CA}"
5) click through them until you find another folder like "{6D62E500-13A0-40F7-966B-A84B121949CA}" and click in that and find a file called "
ROM.zip" - Once you find this, click out of the RUU.
6) Now, rename this "
ROM.zip" to "
PB31IMG.zip" and put on the
root of the SD card.
7) Power down the phone, turn back on by holding vol - down, and power to get into HBOOT.
8) When it asks if you want to update, click yes.
9) Let it do it's thing.
10) Continue with the OP directions to get you some "OFFICIAL 2.2 FROYO!!!"