The fact that Thinkpads are not on the survey probably means that the OP has not been taking close looks at the pictures in a lot of admissions brochures. Although I have noticed a crapload of Dells in pictures, too - I can not for the life of me figure out why anyone would by the piece of useless plastic crap that is a Dell laptop.
For me, there are only two or three real brands of laptops out there: Mac, IBM/Lenovo Thinkpads, and maybe Sony. I own a Thinkpad and could never imagine owning anything else. Thinkpads are, from what I can tell, the computer of choice of the legal profession. And in response to «ě»'s comment: I actually haven't found the Lenovo switchover to be so terrible.
Good for you, and I really do mean that
Many people have, and I expect that the more distanced they get from IBM, the worse it will get. You really don't want to pick computers based on pictures in admissions material. This is just advertising, and advertising will never tell you what the best computer is. Thinkpads being predominant in the legal industry seems to be true, probably more so because IBM/Lenovo are willing to sell them dirt cheap than them actually being the best. That being said, I have had great experiences with Thinkpads in the past, and I have nothing against them at all. Still, the last 3 laptops I've bought have been HP, and they have all been very good and HPs customer service goes miles and miles beyond what Lenovo's does. And even for a geek like me you do need to talk to the CS people every now and then