running some homebrew is possible using gripshift.(from what i know that's limited to a "hello world', a bugged bomberman game, and a pong tech-demo)
using a different bug in gripshift it's also possible to "run" CFW, but that requires files that aren't released yet(releasing this would mean that sony can patch it while it's the only known exploit to run unsigned code without restrictions)
however CFW can't be installed permanently yet(the 2nd gripshift hack only loads a CFW from a memory stick, but can't overwrite the original FW)