We're currently finishing up a new API function that gets the latest activity in your account (new pkeys, new activations, etc.). But I think an API function that gets a list of all the product keys is overkill (and will likely be abused).
However you can export your current product keys by clicking "Export product keys" from the sidebar in LimeLM.
[attachment=0]version-sidebar.png[/attachment]
It sounds like you're trying to build an alternative interface to LimeLM. If this is true, then you could always recommend improvements to LimeLM and we'll implement them.