I love it!
I like Dave's comments, but the info text is redundant by your third visit. What could be nice would be a little [i] logo in the top right of the portlet title bars - these would open a popup (or better, a popup-like hidden div) of the aforementioned info text).
Similarly, a hep icon could be next to the [i] to provide a context help popup. I think help is a major missing factor in our .LRN designs in general.
Also,there are a lot of "My Space" strings! Can we assume that the smaller (and upper) "My Space" String is actually the breadcrumb? If not, where does the breadcrumb go? It's an important part of our navigation, and mitigates some of the concerns raised by Matthias