Has anyone looked at 123D Design (
http://www.123dapp.com/design) from Autodesk as a TinkerCAD replacement?
The desktop version is very complete, and the online version at least matches TinkerCAD in functionality (with some cool things, like fillets, chamfers and editable text).
Would really like to hear what people think.
Disclaimer: I work closely with the 123D team.