Recently I've seen a couple of Hunters in Outland with Plain Striders as pets. Despite what I've read about conventional wisdom on using these as pets, on closer analysis it does make some sense.
Although they don't have the ability to learn secondary damage skills as some pets can, tallstriders do have access to Bite, which from what I've read is a very high damage pet ability. Additionally, tallstriders can learn Dash, (unlike Spiders and a few of the other less commonly seen pets) and get a +5% bonus to base health. The health bonus would make them workable as a tank pet, particularly with the Greater Stamina/Natural Armor trained passive skills. Their animations that I've seen also look good, too.
For my own purposes at least, there are more effective pets around, (I'd never give up my boar, primarily due to Charge, which I really need for the aggro generation) but I remember a BM Hunter I met in the Bone Wastes a bit back who had a tamed Mazzranache, and who was very enthusiastic in his praise of it. Tallstriders also don't get the 10% damage penalty that my boar has, either. For what I do, that isn't so much of a problem, but I know that would bother some people.
Anyone who is at 70 who wants one can still have one, too. Blizzard have included a tallstrider in Terokkar Forest which is level 70. I might actually go and grab one myself at some point, now that I think of it, purely to try it out a little. Could be good for a change, anyway; and I still have a third pet slot available currently.
Although their diet is a bit finicky, one of the things they eat is fungus, so for Horde Hunters anyway, it's not too difficult. You'd need to go back to the Undercity every few days and talk to the mushroom vendor on the upper level. For Alliance Hunters I'm not sure, but cheese is one of the other things they're listed as eating, and from memory cheese is fairly common among Alliance vendors.
A big red plain strider Dashing at something would surely be a sight worth seeing, if nothing else. ;-)