The only problem with Dropbox is that the daemon part of their product is not open source. This is really a pity but it also explains why I started looking at its internals at all -- only to discover that it is written using wx, more precisely wxPython. It's not the most demanding GUI application in existence but it's still nice to see that an application used by many (how many? I don't know but judging from amount of stuff written about it on the web this must be one of the most widely used wx applications in existence) people is written in wx and apparently nobody complains about its GUI.
So while I'll probably mostly continue to use hg myself, I'll certainly recommend it to my less DVCS-inclined friends and relatives. And if any of the readers of this blog want to try it out, don't hesitate to use my affiliate link to register and get extra 250MB of space for both you and me.