scrublover

Assuming you have a relatively relaxed +/- rise stem (as in, only a few degrees) flipping ought not lead to catastrophe. The knee jerk reaction of "you'll endo" is unfounded in reality, unless you're a complete hack on a bike. Ahem. Again, this assumes you aren't going from way high up to way low.
Your head angle isn't altering, just your hand and body positioning. Relatively easy stuff to adapt to, if you like the initial feel.

Otherwise, it may lead to you being stretched out a bit more. If you like it, ride it. You may find if you like the lower front end feeling, but do feel too stretched out that a new stem with the same low feeling, but less length may do the trick.

You get a bit more weight over the front, which can be nice when cornering and climbing. Again, unless you go to extremes with things, it shouldn't un-weight the rear end enough to cause trouble.