Nope, SpaceX is not trying to reuse the second stage. The shuttle reused the second stage (the shuttle) and the booster rockets, just not the 'cheap' external fuel tank.
Remember the second / final stage get's to orbit so return needs a heat shield or an obscene amount of fuel. The shuttle demonstrated the issues with reusing heat shields very well.
PS: IMO, Space X is all about execution not technology. Landing a first stage rocket vs using taking a dip in the ocean is probably a good trade-off. But, most of there gains are about being lean and making incremental improvements.
They are not trying to reuse the second stage of the Falcon 9 rocket. They are planning for full reusability of their future rockets, however. That's what I'm talking about when I'm talking about their plans for full and rapid reusability. This is not something the Falcon 9 will achieve but is in their plans for reusability.
IMO, your overstating things. They mentioned back in 2012 plans for a reusable upper stage and even had a basic video. But, that second stage is a very hard problem and there not actively working on / testing it. So, if you want to include something that's little more than a power point deck then your a far more generous man than I.
ED: It's the classic doing X, trying to do X, or hope to someday do X.
Remember the second / final stage get's to orbit so return needs a heat shield or an obscene amount of fuel. The shuttle demonstrated the issues with reusing heat shields very well.
PS: IMO, Space X is all about execution not technology. Landing a first stage rocket vs using taking a dip in the ocean is probably a good trade-off. But, most of there gains are about being lean and making incremental improvements.