Enough of the speculation: Propellerhead today has formally announced Reason 3 and posted full details. Here's what's new, boiled down:

  • Combinator will let you build combination patches of multiple Reason instruments, as I and others had predicted.
  • MClass mastering suite includes EQ, stereo imaging, compressor, and maximizer. 
  • 'Performance' features:
    better control surface support including motorized faders, new browser,
    new soundbank with Combinator patches and "more sampled instruments"
    instead of just loops. 
  • 6:2 Line Mixer / submixer.
  • Improved automation
  • Improved sample quality, dramatically shorter load times

MClass mastering is mainly aimed at the "create your whole song in
Reason" crowd, but they'll love it. For live performance, the
Combinator could be downright
revolutionary, by streamlining needlessly complex patches. Add reduced
sample load times, and Reason 3 may be the best version to take
onstage, even if it isn't a radical departure from previous versions.

So why is this upgrade stirring up debate?
Many expected a revolutionary Reason release, and this is evolutionary.
When Reason 1.0 came out, integrated soft studios were fairly new; now
the field is overcrowded with endless options. The bottom line is, if
you liked Reason before, you'll love this; if you didn't care then, you
probably won't care now. No, you can't load VSTs in Reason, but Propellerhead is the company that invented ReWire.

And if you haven't checked out Reason before? Now's as good a time
as any. Reason is a tremendous bundle of synths, effects, toys, and
tools. All of this at about $300, with surprisingly minimal system
requirements for Mac or Windows.