• Opening a MIDI file in SONAR will now automatically insert the Cakewalk TTS-1 and route the MIDI tracks to it for instant playback. This occurs under the following conditions:
• A MIDI File is opened directly in SONAR.  This applies to File > Open, not Import.
• No MIDI output ports are available
• MIDI output ports that are enabled are associated with a Control Surface.

This is a great feature!  It's things like this that can really enhance the perception and workflow of software.  At least for me, because whenever I load a MIDI file, the very first thing I have to do is all the routing to a synth (typically the TTS1 in order to quickly audition the MIDI file).  Even if you didn't need this to occur it isn't an issue, so might as well have some reasonable default behaviour
 

Hmm. That is staggeringly useful for a job I have to do from time to time.

Yes, I like it too. I always audition in Sonar; I don't trust the sound of the MS GM as it doesn't support reverb and chorus correctly, and who knows what else. This feature saves quit a bit of time!

Hmm.  Not sure I'd like this for my workflow, unless it were optional.  We'll see (whenever I cave in on X3).

That's odd that they list this as an X3B fix, considering I just did this a couple of days ago.

Does it open all the midi file's settings as well. Like tempo, key, key changes, tempo changes ETC?

Maybe just found it with X3b. I for example didn't know it existed till now as I have a different workflow, auditioning midi files within a sampler already setup.

Hmm.  Not sure I'd like this for my workflow, unless it were optional.  We'll see (whenever I cave in on X3)

 
As it is now, all you need to do is just delete the TTS-1 synth and you're right back to where you were.
 
It needs to be restated that this new behavior of supplying a default synth (TTS-1) is only when opening a (.mid) midi file, not a (.cwp) project file. These are two different animals altogether. If you decide to save the loaded .mid file as a .cwp file, then you will be working on a Sonar project and not a midi file. Of course, you can always save back a .mid file format, but automation will be baked into controller codes within the midi file (as it should).
 

Does it open all the midi file's settings as well. Like tempo, key, key changes, tempo changes ETC?

 
I would assume that Sonar supports whatever a SMF (standard midi file) is supposed to support.

This is a great feature. I always wondered why sonar did not do this.
Having to route every single track to a specific instrument on the tts1 was a pain...
 
But also, this should be optional.
Does sonar ask you if you want to do this when you open a midi file?
 
regards
joni