Just traded my 09 RX for this one, and what a difference! The old style was good, but Lexus has jumped to a higher level of luxury and comfort with the 2010. You immediately notice the much quieter cabin, far-off engine noise, and luxurious interior. The navigation "mouse" appears intimidating, but even this old guy caught on very quickly. The screen is bigger and brighter, and completes addresses after you enter just a few letters, like a computer. Many of the Lexus Personal Settings are customizable from the nav screen, so it's much easier to try some out and then change back. I love this car, and even use it in place of my LS460 at times. Get one for yourself and see.
Navigation controller (it takes a little learning, but works great), cooled seats, comfortable center armrest (finally!), and cushion extender on driver's seat.
Allow keyless entry to back doors, not just front doors and hatch; add a coinholder; move the clock to a more visible position. Nitpicky, but that's how good this car is.