Yeah. I would be interested as well in seeing a batch printing option.
I used to accomplish this (not for UC) by means of a couple of add-ons for firefox, i.e. 'Universal Print' and 'Snap Links', another tool for batch-opening links in tabs.

@nicksageek: How did you manage to grab the data from the DB? Which program did you use to create the invoices?

Thanks =)