I've been monitoring this particular topic as my new ES330 has also been drifting to the left. I reported it to the dealership the same day I drove it home last month. They picked it up the next morning and did a four wheel alignment check, only to make extremely minor adjustments.
This did not correct the problem, so when I took it in today for the initial 30 day check at the dealership, I described it again as a 'drift to the left' instead of a 'pull'. I also mentioned that my steering wheel was not completely level & appeared a smitch off to the left.
After trying several things today (to no avail) my dealership just called me and said they found the problem. Told me it was a known problem to Lexus & there's even a TSB out on it, but my VIN # didn't meet the TSB criteria for VIN's involved, so it was slower to come to their attention. But, come to find out, my ES330 had the same problem described in the TSB which has to do with a strut spring not being installed correctly. They corrected it according to the TSB & said it fixed the drift problem as well as the steering wheel. Can't wait to get it back tomorrow to test it out but wanted to go ahead & share the TSB announcement they told me about on the phone a couple hours ago.
JudyinTX