Here is my reasoning why Acura wouldn't do a TSX with SH-Awd.
1. A 2009 TSX fully loaded with Tech Package could run up to $37K and having a SH-AWD TSX-S would probably push the price into the low to mid $40K and thats pushing into premium market pricing.
2. In the $40K market now, where does that leave the TL? Can't have price overlap with Acura's bread and butter so forcing TL into the low $40K for the base TL to upward of low $50K for the TL-S. And TL is will still be FWD car even the upcoming 2009 TL.
3. If the TL pushes into the $50K market, that will lead to Acura pushing the RL into high $50K-mid $60K market which includes A6/8, LS, S/CLS, 7 series market which the RL was clearly not designed to compete in and the RL is not due for a full redesign until at least 2011/12.
4. An Acura personnel told me that the TL will be the only Acura with a Type S model.
5. Beside just because TSX could fit a V6 doesn't mean they will stuff a V-6 plus SH-AWD hardware into it. If thats the case, current TL would have been available with SH-AWD since 2005/2006.

I just don't see Acura being that bold with the TSX especially with CAFE's 35mpg standard by 2012 being imposed.

 

While not disagreeing with your conclusion, I think you factored too much into your point #2. Mainly, I think if they were going to go the SH-AWD route, they'd use the RDX drivetrain before developing a new smaller V6 mated to a new SH-AWD tranny. In this form it would not be competing against the TL anymore as the market for a 4 cylinder turboed small sedan is quite different than that of a larger v6 sedan. For instance, the Audi A4 does not much step on the toes of the A6. You're average shopper is going to be fairly strongly biased towards one or the other. The role they each fill have little overlap.

Personally, I'd rather see a turbo engine mated to an active differential for a SH-FWD. From a performance standpoint (the main point of a Type-S version would be the performance after all), the TSX would not stand to benefit a whole lot from SH-AWD without a large, gas sucking bump in power. The chassis is so fantasticly balanced for FWD that there's little need for powered rear wheels. If you could get those front wheels to hook up even better you'd have a FWD car approaching the handling of the BMWs and such. Plus you wouldn't get the added weight and driveline loss from the AWD.

I kind of doubt it's going to happen in the current economic and ecologic climate though. It would likely be a money losing venture for Honda.

 

Correct Jay, except:

Accord Coupes have a lower stance and slightly stiffer ride anyway...but you are going to toss the stock suspension pieces for aftermarket.

Accord Coupes are marginally lighter due to less hardware (two less doors and a small enclosed area).

The V-6 is a much better autocross engine that our rev challenged I-4.

The Accord is way over engineered...in a similar manner that the TSX is as a Euro Accord.

The problem is the 6-MT only just became available in the V-6 Accord...so there is always the thought of an old CL-S as a racer...

 

1- that is just as speculative as my thought is. Consider the SH-AWD and upgraded powertrain accounts for a $4000 or so premium in an RDX over the TSX. That would put a TSX in the $35K range at most.
2- the 09 TL will have to be better. Don't forget it too is getting SH-AWD.
3- don't get too carried away here...
4- An acura dealer or an actual AHM employee? Because I know more than a few people at AHM and those who KNOW things are tight lipped, and those who HEAR things know as much as we do.
5- The SH-AWD system was first released on the KB1, then on the RDX. Both of which came out after the UA6 body was designed. There is no way they could put SH-AWD in the TL until a full body redesign...ala 09 TL.

Don't you think that CAFE standards would be met with the averaging of Base, Turbo Diesel and V6 TSX all being offered? The Diesel is coming, without a doubt.

Marcus