AppSync is a great update mechanism for certain use cases (more information on the AppSync feature can be found here). When you have deployed a new version is it very likely you want to perform a new thinreg registration on the package. AppSync has built in support for thinreg. If you place thinreg.exe on your AppSync URL will AppSync automatically perform registration of your new version.
Instead of just writing about it have I created a video showing you the functionality. In this video am I using a UNC path but HTTP/HTTPS will work just as well.. Please enjoy..
Direct link to video: http://vimeo.com/channels/thinapp#36375955
Yes, pretty cool indeed..