This release looks like a great upgrade to a great library. The idea of using python as my "one language" is really appealing, but I still find myself falling back on R pretty consistently when it comes to data manipulation/analysis. As pandas matures I see myself doing this less and less.
I'd be interested to see some of your R use cases where you perceive that things could be improved in pandas; a year ago there were lots of things you couldn't do, but a lot has changed :) Nowadays, the tables have turned and there are lots of things you can do in pandas that are nearly impossible to do in a non-kludgy way in R (particularly many things with hierarchical indexing).
Wes - I think that the reason I would keep using R over pandas is all the packages in the R universe. Which I suppose is the reason why you would use pandas over R if you had more experience with python.
E.g. ggplot2 still seems to be quite a bit better than matplotlib. Also for the random data examination/sketching I absolutely love rstudio due to it's integrated help/plotting/file browsing.
I guess it's been about 9 months since I really put pandas through its paces, so I'll take another look. IIRC, last time I really tried to do a project with pandas, I found some typing/data transformation issues to be the things that held me back most. If I find some time in the next couple of weeks I'll try to put together some concrete examples.
Thanks Wes and everyone else who pitched in!