Actually, I sold my iPad 2, and had my iPhone up for sale, and bought an Asus Transformer Prime and a Nexus S to give Android a whirl. I think that experiment lasted about 2 weeks. The app selection for Android tablets sucked, as far as the kind of apps I wanted. They were just "bigger" versions of the phone apps, much like the doubled up iPhone apps on an iPad. I also really disliked the web browsing on both Android devices, and didn't find a browser that made me happy enough to keep them.
So I sold the Transformer Prime (and keyboard) for what I paid for them, since they were still in short supply, and bought a low-end iPad 2 to tide me over for the new one. My GF (who uses a Galaxy S2) put up with me through this process, and is also going to get an iPad 3, although she won't switch phones.
One thing I did miss about the Android devices was the widgets/gadgets/WTF they call them that you can throw on, and move around on your home pages. But that wasn't enough to keep me 'droided.
The pen thing might be nice, but not for the kind of thing I've been using my tablet for. And who knows, with having Bluetooth 4 on board, maybe we'll see some cool stuff come out for the iPads too.
C