I am predicting that a year from now Shen will be considered lower than he's generally considered now, and Joe will be considered higher.
I think that right now everyone's impressed by Shen's high damage and high abare, but he really lacks tools to open people up since the console changes. His jump-ins have to be done extremely late (later than most of the cast) if he wants to combo off of them, making him extra susceptible to anti air. His c.B,c.C link is not terribly reliable as it's a very tight link with extremely close range requirements, and his only other decent low option involves having full HD gauge. His overhead is unsafe at all points now, even the EX version. He eats a full combo (often to death) if he attempts any sort of overhead and gets it wrong. So his low options and overhead options are lacking. His grab is solid, but it's not enough to make him high tier. His defensive options without meter? None. He's pretty much completely free to pressure against if he doesn't have at least the meter to guard cancel. I would like to say he's middle. He has pros and cons, and when your only pro is "lol damage", then that's not good enough, because the entire cast can deal crazy damage.
Joe is a fairly complex character with potential that's not been tapped, particularly in the corner combo department. Just wait a few more months and I'm betting that people will have figured him out a fair bit more. Right now I think people just compare him to Hwa, and he's not as strong as Hwa, but he's still got some tools that Hwa does not, like zoning.
That's my rant. Certainly lots of characters will be shifting around the tier lists over the next 6 months, but those are my predictions right now.