I am not sure of the exact dates, but based on when I noticed the were open and when I was informed they were closed: R.I.P. Merpoint, Jan 2010-November 2010.
However their website is still up, so I guess this is unconfirmed?
Oh, wait, their Facebook says: "As of October 19, 2010, Merpoint Publishing has closed it's doors for business." So I guess that makes it official(ish).