Don't know about specific conditions right now but I've done that in the past in later March, Marcy to Gray, and it was quite easy. You're up on enough snow that hunting for the path isn't a concern, you're really just going along through the tree tops. In summer, of course, it's different, and everyone's right, Gray to Marcy is easier because the path is well-defined coming off Gray and once you hit treeline at Marcy, you just head up the rocks. In the other direction, you'd have to be sure to find the entrance to the path or it'd be some nasty bushwhacking. But I think even with this year's snow cover, you won't have any trouble going Marcy to Gray. When I did it, the whole top of Gray was buried in snow and you could just wander around everywhere - it was pretty cool. That was back in cannister days and the can, which was quite high up on a tree as I recall, was buried in the snow.
P.S. - If you're headed down to Lake Tear from there and out via Lake Arnold, a really nice route is to backtrack to the Gray-Marcy col and just follow the drainage down to Lake Tear. It was pretty open and a pleasant walk or ski. Funnels you right down to Lake Tear and you pick up the trail from there.