I was just looking around for any updates on this project, and I noticed a permit request filed last week --
https://www.ci.austin.tx.us/devrevie...erRSN=10901876
It's just a permit for benches, lights, trash receptacles, bike racks, etc. So I don't know if it's a temporary use of the lot for something like SXSW, or if it's related to the overall project. It is the hotel developers applying for it, and the overall hotel project permitting appears to still be in progress (started in Oct 2012 and the most recent update is Feb 20 of this year - look up 101 Red River in the permit search to see).
I would love to see this under construction soon, obviously all of us would. My hope is that there will be two 800+ room hotels with cranes up in downtown by F1 weekend in November. That would be awesome.