I just made a Turkey meatloaf, using a standard recipe that usually turns out good with ground beef, but it was too dry - any help would be appreciated. 
Avery's "fattest turkey" advice is solid.  I try to find ground turkey breast as opposed to ground turkey, no matter what I plan to do with it, because it's easier to keep it from drying out in various recipes.  As he said, ground turkey is so easy to overcook.  You could always add some moisture by throwing some bacon grease into the mix, which I have done in the past with regular (ground beef) meatloaf to help make it as unhealthy and delicious as possible.  This should effectively counter the health benefits of using ground turkey over ground beef, but boy is it good!  When my mom makes turkey burgers for the grill, she adds some italian dressing into the mix and swears that it helps keep the burgers from drying out fast.  Haven't tried it myself, but I can see how the oil (and water and vinegar, but moreso the oil) would help.  It will likely affect the taste of the dish...but that isn't always a bad thing, as I find ground turkey to be significantly more "boring" tasting by itself than ground beef is by itself, probably because of the lack of fat. 