The people developing RStudio have done it again!
I have been using for a couple of days RStudio from the 0.99 version previews, and it is working extremely well. The new functionality improves very much the easy of use: now there is auto-complete and automatic “bubble” help, both are a hugely helpful when writing scripts and package code.
You may still want to wait, as new versions are being released almost every other day. Anyway, I wanted to share the good news.