As far as I understand it's tested fully, although I don't know what the actual test cases are. Also, at least earlier there was a separate Ovi QA and Maemo QA but I don't know if this has changed since.

And just to clarify, my intention wasn't to rant about Ovi or their QA. I just brought this up as an example of things that can affect the schedule which we have no control over. The date when an update is ready from production and when it actually hits the stores can differ quite a lot. In some cases and platforms it can be near instantaneous (minutes) while sometimes it can take very long time (months).