Monster Squad is an all-time favourite mine, so I do hope it comes out officially on DVD someday. Until then, someone on the DVD Talk forums posted that:

For anyone interested and has VOOM's MONSTERS HD ( Dish Network ), they are showing it again this month.
JUNE 17 - 9:15AM
JUNE 24 - 8:15AM
JUNE 25 - 11:00AM

Not sure what time zone those are though. So if you happen to subscribe and have a DVR or DVD recorder, now is your chance to get a really nice copy.

If anyone who's capable of grabbing it this month (and hopefully in OAR), it sounds like it would make a great start for a preservation project.