Noticed a little extra bugginess when it comes to landscape mode in 2.1 in conjunction with opening and closing the slider. Opening and closing the slider to switch display orientation sometimes freezes the display somewhat, in that you can't switch between the 5 homescreens - it gets locked onto the first main screen. I can still choose apps on that screen I just can't slide over to an adjacent one. However, the phone is not frozen, pressing the home button and re-launching (I have not default set this) will unfreeze this.
Fairly minor but worth mentioning.