It is way more time effective to correct, move and even quantize midi data then audiosnap actual audio.  Believe I should know, I have spent at least 60 + cumulative hours using audio snap on drum tracks in the last 6 months.  Oh my goodness.......it is working much better but it is sooooo tedius to correct each track or section of a track, bounce it to clip and then make sure audiosnap is off as half the time it is not REALLY off and there are little munchkins trying to finish transient detection etc.
 
When aligning drums one has to also multi-select and align the overhreads and room mics with every single adjustment, to keep everything inline.  (not for bass drum if your highpass your overheads) ...Anyway,
 
So this time I  took the midi from audio snap went thru measure by measure, got every bass drum , snare roll and stuff where it needs to be...uggh.   NOW....! I like the real sounds better,  wouldn't it be cool if I could enable audiosnap on the real snare track and and have it source the midi and align itself????
 
How bout the bass drum? toms? even the overheads , some super duper algorithm could  guess where the transients should go on the overhead audio and allow fine tuning , all based on the midi of the snare, toms or a hi hat track?  I would mic the hi hat if I knew it could help go from midi to audiosnap.
 
I have most of the best drum vst, none can beat having a little or a lot of the real drum mixed in,  cant do that unless one painstakingly snaps the real audio being sure to bounce often right now, then gets the midi, renders and checks for alignment, maybe move the midi tracks up a few ticks to match the audio etc....it is just very tedious and I am very patient.     Is there a way to get midi to help align audio? and should there be? am I just nuts.
 
 

There are workflows/techniques you can use to acheive this in Sonar. Keeps studying and they will reveal themselves.
 
For now realize you can use MIDI to alter your timeline and then you can snap your live audio in audiosnap to that timeline.
 
Drum Replacer opens up a mountain of other options (like you can insert samples of the original drums into the Drum Replacer instead of prepackaged samples or even create your own sfz files to use with drum replacer using multiple samples of the original drum files).
 
So yeah... it already exists. It's advanced stuff though and you gotta be clever, imaginative and willing to put in the work/study.
 
I have come up with multiple theoretical workflows for exactly what you are describing but have yet to test them out and they would take a reeeeally long post to describe (longer than my usual diatribes).
 
Use yer noodle and it'll all come together eventually. Have fun.
 
PS: And Session Drummer 3 will also load and play raw samples/sfz files if that's what you're looking for. Create your samples from the original drum track(s) (trim, treat, export, whatever) and load them right into the kit slots of SD3 or create an sfz for velocity sensitive multisample goodness. SD3 doesn't have a lot of the ultra fancy stuff the other samplers do but it allows you to do stuff like that and is a pretty solid drum machine. Most of the ultra tweaking that the other drum programs offer can be done on the audio outputs with the effects in Sonar (if it's not already available in the SD3 program).

There's "groove quantize". Is this what you want? (what beepster refers to, I think) You have a midi clip with timing you like. You promote that to a "groove". Save the groove, or leave it on the clipboard. Then apply the groove to an audio clip, which is said to move transients around to match the groove. In the manual, find "groove quantize". Dunno if it would work the way you want on multiple instruments in the track.

Thanks Beep ( nice picture, I have two Bernies) much to think about, I have always liked the simple look and feel of Session Drummer.  So I can expand that with the tons of SFZ libraries or create my own.  When you say modify the timeline with midi then snap the audio to the new timeline, were you referring to groove  quantize ? as bvid was thinking above?  I don't use groove quantize but from the sound of it, I should learn more about it. 
Groove quantize , in a long song with breaks, verses , bridges etc.  would you likely create a "groove" with each pattern type individually? or can you just turn the  stinker on and it just learns the whole track?  
 
anyway, good direction for me to head gents, I appreciate the responses a great deal.

So I selected the entire bass drum midi track (perfect in all its glory, this is a metal band with craploads of double bass ).  I selected PROCESS-GROOVE QUANTIZE- and clicked the DEFINE button.  Named the container file (test) and named the groove (test) and saved.
 
I went to the bass drum audio track selected the entire track , chose VIEW-AUDIO SNAP PALLETTE- and enabled audio snap on the track by clicking the power button in the audio snap dialogue.
 
With the track still selected I went to PROCESS-GROOVE QUANTIZE again and this time just selected my new groove called test.  In the option of what to do if outside the windows I selected move to nearest. 
 
I clicked OK and I watched my audio (with the transients still highlighted) SNAP in line to the above midi track.
 
It was beautiful.  I laughed and then I cried. 
 
Then I realized that on this particular bass drum midi track I may have actually added or removed some midi notes after exporting it from the audio.  That is a problem for another day. This is a really nice thing you helped me figure out guys.  Thanks.