I've just spent the last several days at a local Lexus dealership and put a deposit down today.
Here's exactly what I was told:
1. You can get the ML sound system but you have to order and it's at least $1K extra. Ordering takes about 3 months but you're going to have to wait for the car you want anyway. They are selling very fast.
2. The car is pre-wired for XM & Sirius but you have to buy a separate receiver that is about $400 through the dealer. This is for either the standard sound system or ML. I imagine you can buy the receiver elsewhere for about $100.
3. The first batches of cars are also not shipping with what they call the Luxury package, which adds to the Premium Package: power tilt & telescoping steering column (standard is manual t&t), memory seats, illuminated scuff plates, rear window powershade, HID adaptive lights, rain-sensing wipers. Again, this can be ordered, but it's about $2K more.
4. The are selling these cars at sticker price, even to repeat customers like yours truly. You can see the sticker if you 'builid your own' at Lexus.com.
5. I drove a 350 and it absolutely ripped... Very, very fast but also incredibly quiet and refined. I was impressed.
Hope that helps. I learned a lot the last few days.