Actually, we DTrace folks left the company[1]; the people doing the DTrace port to Linux are solid engineers, but they're not from the Sun acquisition. For more details on them and on their perspective on the port, see Kris Van Hees's excellent presentation at dtrace.conf last year.[2]
[1] http://www.youtube.com/watch?v=-zRN7XLCRhc#t=44m16s
[2] http://www.youtube.com/watch?v=NElog3MvUC8