Hi,
 
I just watched a video from Sweetwater featuring Craig Anderton. https://www.youtube.com/watch?v=RsbVAykvZBg
The part that caught my attention is the tempo extraction which starts at the 4:00 minute mark.  A laid down guitar track which speeds up and increases tempo speed is dragged into the timeline and Sonar opens AD and the drums follow the guitar track.
Can this be done in x2 with the free download of AD 2?
If not, what do I need to make this happen?

RCT
 
Can this be done in x2 with the free download of AD 2?
If not, what do I need to make this happen?

No, X2 does not do this. Melodyne Tempo Detection was added to SONAR 2016.03. You would need to upgrade to SONAR Professional or Platinum.

The AD2 part is MIDI and is just following the timeline as any MIDI part would. The 'trick' is making the timeline's tempo map follow the guitar track, which is being done by using Melodyne 4's Drag Tempo to Timeline function. IIRC, Melodyne Essential was not bundled with SONAR until X3 so X2 would not have this capability out of the box.
 
I should note that Melodyne Essential has a stripped down implementation of Drag Tempo to Timeline that doesn't allow fixing any mistakes it makes in extracting the timing from the audio clip. Naturally, the clip that Craig used in his demo was chosen to produce a good result.
 
The good news is that X2 has Audiosnap which does essentially the same thing, though by clicking the Set Project from Clip button in the Audiosnap Palette rather than just dragging the clip to the timeline. Like Melodyne, it will work perfectly on some material without additional steps, but will require massaging the clip's tempo map first in other cases.

Thank you,
So, Sonar Professional will actually do this. That's great.
If I buy a download version ( or do they send a disc?) can I transfer the download to a computer that is not online.
If it's the download only can you tell me how to get it off this computer and on to my music computer?

You can download the installers directly from the website (assuming you're logged in with the account that you used to purchase them).  Go to "Support" | "Product Downloads".  These can then be transferred (via pendrive or whatever) to the offline PC.  Note that you will also need to carry out an offline activation of the product, see instructions at:
 
http://www.cakewalk.com/Support/Knowledge-Base/2007013384/Offline-Activation#sonar
 
AMB
 

Thank you

I'm not sure if this is relevant of helpful to your question, but you can sync AD2 to the Host comptuter on the 'Beats' Page of AD2, so it will be in sync with a changing BPM in Sonar

Thank you everyone.  Looks like I will be upgrading to Sonar Professional.