The advantage to MeeGo is that it is not bound to Nokia devices.
There are some inescapable bits (thus far) with all ARM devices, namely the 3D drivers and the like tend to be closed. The only handset without this issue seems to be the Aava devkit but, well, yeah.
The -core- of MeeGo is open, which is important. And thus far, it's possible to assemble a MeeGo image with the closed bits pulled in. With luck, anyone should be able to pull those closed bits themselves and merge them with whatever (Linux-based) OS you want to install.
Getting a fully open device would be REALLY FREAKING NICE, but lacking that is not a reason to push towards Google's platform in lieu of MeeGo, IMO.
Driver and binary blob situation being equal between MeeGo and Android, MeeGo is not controlled by Google exclusively. That exclusive control (and single source dependency) makes vendors like Motorola nervous. MeeGo's independence is attractive from the same standpoint that makes the Linux kernel attractive, and hopefully will draw in vendors.