Krait comes out second half this year.
It all depends how long you are willing to wait.
Krait is actually Q2, though it's more a May/June thing I think.
I think the decision is pretty simple, and it really relies on how important LTE is to you. If you are on AT&T and feel HSPA+ is fast enough for you, you can probably safely buy non-LTE phones like the Samsung Galaxy S II and iPhone 4S. However, if LTE is appealing but you demand good battery life, you're going to have to wait for 2nd generation LTE chipsets, and that's Q3 at earliest.
I caution you to avoid any LTE phones that in their teardown are still based on the MDM9600 or other 1st generation LTE chipsets, especially on Verizon. I don't think the battery life is worth the speed, especially when slow CDMA will tempt you to rely on LTE for speed.Future LTE phones are going to have much improved battery life, making using LTE not such a pain.