Android 2.3 (2.3.3 actually on HTC Desire HD), also known as Gingerbread, is being released in europe these days. Link to information form HTC: HTC Support.
I forced an upgrade using menu->Settings->About phone->System update->Check now (translated from Danish).
A few notes on the cleanup I had to do afterwards.
After upgrading to 2.3.3 my Lotus Traveler calendar was full of entries with no subjects.
To clean those up i used Programs-Notes Traveler->menu->Tools->Replace data
I checked all three options and clicked OK. I could probably have just done the Calender, but just to make sure I did all three.
This took a while to complete.
Afterwards the Calendar was just fine.
Picasa Web Albums
After upgrading i got regular notices on the device that Picasa Web Albums was forced to close.
After trying to turn off and on and still seeing the message i removed and re-installed this HTC-addon. Which made it work again.
This is an HTC addon, so removing and re-installing is not done like regular Android apps.
Programs->HTC Hub->Applications and plugins->Swipe to see Picasa-webalbums->Remove
And then (waiting 5 minutes) re-install:
Programs->HTC Hub->Applications and plugins->Swipe to see Picasa-webalbum->Install.
If you haven't had this addon installed before, here is an explanation on what it does: It makes it possible for you to access your Picasa Web album photos from the Gallry App on the device. And it also makes it possible for you to post (share) photos to your Picasa Web Albums account