Next trendy open source projects

If past is any indication of future trends, surely next trendy open source projects will be what's currently developed at technology leaders like google.  Similar to hadoop becoming popular after google published its map-reduce paper, and then big table implemented as hbase by open source community, surely there is a cool factor as well as value and following in building open source implementations of:

• tenzing
• dremel
• pregel
• megastore
• spanner