The relevant part of the conditions [1] simply state that

> You may use the software for testing purposes only. You may not use the software for commercial purposes. You may not use the software in a live operating environment.

So there's nothing inherently wrong with testing desktop apps, but the non-commercial clause may cause problems.

[1] http://modernievirt.blob.core.windows.net/vhd/release_notes_...

Cool! I've been testing open source apps in an adhoc fashion with these, but was worried about licensing.

I guess I can automate and document this now :)