Hey Steve,
You said the TA3.3 would automate the revocation checks and only do the check every now and again (not every time the app starts)
Yes, that's included in TurboActivate 3.3. IsGenuineEx() is the function that you want to use. If you tell me what programming language you're using then point you how to use the new function. Also, note we've updated all the example code and articles to use the new IsGenuineEx() function. See: Using TurboActivate.
So how should we perform revocation with the Dat file?
The dat file isn't the license file. It's a "product details" file. (Basically it's information TurboActivate needs to know in order to activate your software).
Just use IsGenuineEx() how we recommend to and everything will "just work".