This is what worked for my EVO - a modified version of posts 66 and 74 (mucho thanks to Wagebo and greg.dr). I had to sync for each year manually.
1. From the home screen hit menu and go to Settings - Accounts & Sync.
2. Turn off the Background Data and Auto-sync.
3. Switch to Airplane mode to disable phone and GPS (because if you get a call or sms during the process, it corrects the time), then re-enable Wi-Fi so you can sync.
4. Go to Settings - Date & Time.
5. Turn off Automatic then Set Date to your earliest appointment year (e.g. 1/1/97) and hit set.
6. Restart phone.
7. Go to Settings - Applications.
8. Select Manage Applications and choose All.
9. Find Calendar in the applications list, select it and choose Clear Data (it will warn you about losing all files just hit OK).
10. Do the same for Calendar Storage.
11. Go to the Calendar application. Choose Menu - More - Calendars and select All calendars. Make sure each calendar type is checked.
12. Go back into Settings - Accounts & Sync.
13. Select the Google account, then tap Sync Calendar to sync. Do not sync gmail or contacts.
14. Be sure the date it lists for the last sync is the date you selected, and you may want to hit sync once or twice more to be certain the sync was completed.
15. Once sync has completed for the year selected, choose Settings - Date & Time. Change the date to Jan 1 of the following year (e.g. 1/1/98). Complete steps 12 - 14 for the new year.
16. Repeat step 15 for each year until the present year.
17. Once complete go to Settings - Date & Time and select Automatic.
18. Go to Settings - Accounts & Sync and turn on Background Data and Auto-sync if desired.
I ended up with 7.10MB in my Calendar Storage database and it took about 30 minutes for this process. Hope this helps until Google fixes this glaring problem.