That's probably correct, Matt&Team want to squash as many bugs as possible with frequent patches following final. I'd expect a few more patches at least after 3.0.1 in the near future.
I'm not sure that's enough for saying they are copying although the IP.B3 preview site was out before they announced any of that, who knows. No one can say for sure...
You'll be better off to contact sales@invisionpower.com they will be able to tell you exactly what can be converted, as far as I know, SMF 1.1 can be converted.