I tend to agree with Tim. A lot of (most) clubs use their region in their name. Westgate brewers is a great example. Other clubs use funny names (I reckon Worthogs is brilliant). Some do both (How good is "Too SOBA"?)
Merri Mashers kind of does both. Merri gives both a locational aspect, as well as having the jovial/happy meaning. I think having the spelling as Merri distances it from being too juvenile. Mashers even makes it a bit Gen Y given the whole "mash up" thing those young interwebby whippersnappers are into. Northern Brew Club sounded too generic for me (north of what?), same for using Melbourne in there.
I tried to come up with some kind of mash up (see what I did there kiddies?) of our local councils, Darebin and Moreland. But Morebin sounds like what you do with a bad batch, and Dareland sounds like somewhere you go to buy sex toys, so I gave that up pretty quick. The only other name that struck me was Bell Street Brewers/Brew Club.
But the guys are right, the whole thing needs to go to a vote. Let's not get too bogged down on it, the fact we're even on the verge of a viable club is a lot more important than a name.