I was smart enough to keep a list of all my bugs so far so I could eventually report them. By the way, in case you don't know (or don't know how to use Google), you can report these bugs to Apple at
http://developer.apple.com/bugreporter/!!!
My Setup:
- MacBook 13" Black (Summer 2007)
- 2GB Ram
- 64GB SSD internal hard drive running Lion
- 500GB HD automatically mounted as /Users
- Fresh Lion install
- Used the encrypted formatting option in Disk Utility
- Enabled Server during install
Problems with OS X Lion
- Apps can sometimes disappear due to an issue with Spaces (presumably) and can't be visible again until a restart of the app occurs.
- Launchpad can crash sometimes when you rename a folder
- Can't delete Launchpad folders that are empty
- Multiple versions of two apps exist: Transmission after an automatic update (Transmission crashed during the update and now there's two listed, as well as a failed MacVim install that lists the app twice also)
- When adding an app to a folder in Launchpad that already has the max allowed, it lets you drag and drop it, then "crashes" that folder (sort of shrivels up and is unusable until you restart the dock)
- iChat sometimes quits when you close the window (using the red button or keyboard shortcut; I do have the feature enabled where all accounts are listed in a single buddy list which may or may not be doing it)
- iCal unsubscribes (randomly) from delegate calendars synced with Google Calendar. Sometimes at app launch, others during other actions within iCal.
- iPhoto crashes quite a bit, but it's a very fast crash and relaunch, which is nice.

- Bluetooth mouse (magic mouse) is at 100% battery life permanently (previously mentioned in this thread)
- Moving the mouse or trackpad to wake the computer doesn't work, but clicking and keyboard does)
- iChat won't open for me as of this writing, although it has previously. Going to try restarting.
- Mac App Store crashes upon open, which is a new development also. Going to try restarting.
Problems with 3rd Party Apps
- Transmission is crashy. Having miscellaneous trouble with it including using its automatic update feature.
- Silverlight doesn't work! I'll have to set up VirtualBox to watch instant stuff on Netflix.

- Evernote doesn't work (at least the app store version, anyway. previously mentioned in this thread)
With all of that, I still find that there's a lot of cool stuff that makes using the developer preview worth it for me. I like how spaces works now (when it works) and the improvements for SSDs (whole hard drive encryption, TRIM). I haven't figured out the versioning app yet, but I bet it will come in handy. iChat has some improvements, when I can manage to keep it open, and Address Book has the ability to add Facebook, Skype and more to instant messenger entries. Syncing with Google Contacts is much better. iCal looks amazing.
Most problems can be solved by a reboot of the computer or an app in my case.