Source: http://forum.nasaspaceflight.com/index.php?topic=30385.msg10... (and generally a good place to look for SpaceX updates...)
There's a Grasshopper 2 plan in the works (using a v1.1 tank) which will supposedly have rather more flight-like legs than the current one.
But I'm sure that a lot of what they've learned from Grasshopper will be going into the June test.
For a relight, you need some propellant at the feed pipes to restart, though if you have small enough aero forces, you could just vent some stuff to accelerate the rocket forward slightly so you can start ingesting liquid again, instead of the pressurant gas and can then proceed with relight.
Then again, since the empty rocket's bottom end is heavy, it could orient itself the right way aerodynamically anyway (acceleration vector pointing the way of the nose) so the liquids go towards the engine end.
If it comes like a dart and not tumbling (which presents its own problems), such a big stage has lots of mass per frontal area and it will come in quite fast.
Interesting aerodynamic problems. I wonder if we might see some maneuverable mini fins or wings at some point.
Keep in mind no one has successfully done powered vertical landing from orbit. It's never been done. (Well, not from Earth orbit anyway. The LEM landed vertically from lunar orbit.) SpaceX is getting a taste of how hard this is by trying to recover their first stages using parachutes - their every attempt to do so has failed.
If they could focus the bulk of their engineering workforce on this problem they might be able to do it faster. But they have to massively scale up production to meet the orders they've taken, they have to keep their reliability up, they are constantly working on performance upgrades for Falcon 9's engines, and they have to get Falcon Heavy going to crack the DoD market. Oh, and there's this little thing called Dragon and NASA's Commercial Crew program. Something about launching those living sacks of meat and bones we call people tends to hold your focus pretty intensely.
http://www.space.com/13140-spacex-private-reusable-rocket-el...
I'm sure they'll start with just the first stage, but you can't just do a powered descent - that would leave it in the middle of the Atlantic ocean. It has to be a return-to-launch-site maneuver and landing, which is what you see in the video linked to above. At the point where the vehicle does a 180-degree turn (referred to as a "death swoop" by rlv enthusiasts), it's going Mach 6 and is 1000 miles downrange. That's hard.
What SpaceX is doing is totally awesome but – for the foreseeable future – a risky business.