Of note, the use of GPS for surveying sea surface height has proposed or experimented with for a number of years (Cardellach, Estel; Martin-Neira, Manuel., April 2010). It might be because they've moved beyond 'proof of concept', but I think to say they discovered it is a bit strong. I've even found papers detailing the experimental use of GPS satellites to determine sea surface heights as far back as 2001 (Martin-Neira, M; Caparrini, M; Font-Rossello, J; Lannelongue, S; Vallmitjana, C S, 2001). The bggest change might be a reduction of errors, going from (30cm errors in 2000 to 5 - 15cm in 2009. If they've managed to further reduce the size of the errors then they're onto something really big. If they've just found a more efficient method of measuring sea surface heights in the open ocean, well that's pretty cool, but I'm not sure it's quite a game breaker.
As far as sea surface rise being a hoax, that's a silly statement, after all the empirical evidence is pretty strong, We have long term gauges that have been operating for centuries in a number of areas, and excepting for regions of crustal rebound, raw sea level rise is consistent with expectations if additional heat was being pumped into and inceasing the depth of the thermocline..
As in certain cults it is possible to kill a process if you know its true name. -- Ken Thompson and Dennis M. Ritchie