You can get them on toysrus.com now and some retail TRU stores probably have them, I say this because a few of my local stores are showing 'in stock' for some of the other march 2014 sets (like SW and Super heroes), but not all the sets have the "find in store" option yet. TRU website is kinda iffy that way.
also amazon.com has SOME of the march 2014 sets for pre-order (for example, here is the
Eagle Legend Beast, but the others don't have a Sold By Amazon option yet), shipping March 1st on those. Sadly, as is the new trend with amazon, they have chosen to markup the sets from 9.99 to 11.99. there's a similar percent markup for many other sets, particularly small sets. I'm sure it's a shipping thing.
Don't overlook Mixels if you are interested in the new joints. Those should be popping up at TRU soon too.
Finally, you can get most of this stuff already from shop.lego.com and free shipping... so why wait? Granted, the shipping from them is a bit slow... expect to wait a minimum of 7 days, more like 10 if you order near the end of the week.
On another note, nothing to do tomorrow so hitting up the LEGO store after work. who knows what I'll bring home. It's a mystery. (No Sea Cow though, saving that...)