I came from a BlackBerry Curve 8330, and so far my biggest learning curve (no pun intended) has been in getting used to the swapped positions of the Alt and Shift keys on the D2G physical keyboard versus the BB's. Other than that, I am loving the responsiveness of the screen, the MUCH better internet experience, and being able to find so many free apps that actually make the machine more useful both as a phone and a computer. I do, however, find copy-and-paste to be a monumental hassle without a trackball to quickly select text. I pray that is improved a bit in 2.3--which, knowing Verizon, I may not see until Christmas.
In just the week-plus I have been using my Droid 2 Global, I have found the battery life seriously lacking--4 hours versus 8+ on my old BB--but like others have mentioned, I have chargers everywhere--car, bedside, and even tethered to my desktop right now. (Using PdaNet for tethering. Sweet!) Plus, my new Bluetooth headset interfaces much more thoroughly with the Droid than on my Curve.
As for the task killer debate, several of the min memory apps mentioned work best if you have root access. Being the cautious, warranty-loving dweeb that I am, I am not willing to risk bricking my lovely new phone. I went instead to Smart Task Switcher, which allows me to kill apps that haven't closed out, and which also gives me more apps to switch to than the long-press on the Home key. Other than that, I let Froyo work its magic.
Take advantage of the 30 days or whatever you have to get used to your new Droid. You may indeed find it is better than you at first thought.
In short, loving my Droid!