[botj]

Probably not for a while. At this point octave has a TON of Matlab compatibility:

The grammar is pretty spot-on although there is usually some release latency when Mathworks changes it (obviously since their plans are not made know. Ahead of time).

Octave even has Matlab source level compatibility for mex files although they are slower than octaves own c interface.

If you start drifting away from Matlab core needs into the specialized add ins Mathworks provides (simulink, financial packages, etc) then Octave can't help. If you need those then I find that Matlab is rarely the tool for the job either (you just don't know it yet ;))