OOo writer offers explicit Mail Merge option for Letters. Apart from it, it 
also offers mail merge options for labels and business cards, although at 
different places in the User Interface.

How about consolidating them at a single Place (and extending it) to make 
things easier for the users.

Menu Options for it, may look like this -
Tools -> Mail Merge -> Letters
Tools -> Mail Merge -> Labels
Tools -> Mail Merge -> Envelopes (New feature)
Tools -> Mail Merge -> Business cards
Tools -> Mail Merge -> Emails (New feature) (Generation of Multiple Emails, 
which will be forwarded by standard Email clients like Out look or Mozilla)

Thanks