I've noticed this too. Altho at least 25% of ppl at my uni who had laptops seem to have macs, the statistic was more surprising on the train to and from uni, where there was at least that amount but the users tended to be professionals. What's most interesting about this is that I left uni last year, so my point of reference is before the intel switch.
TBH, I think its just that Mac users are more likely to use theirs in public cos they tend to be prouder of them. Lots of ppl buy windoze laptops and don't use them after a year cos they get so crapped up so quickly and they can't be bothered to reformat them. Often I'm surprised to learn that some of my friends even have them cos they never use them. Some student friends of mine were making heavy use of a single mactop for their entire 4 year degree. However, I would expect Apple to have double the marketshare in laptops vs desktops, simply because laptops are fragile and bitty but Mactops feel like a unified whole rather than a bunch of downsized components encased in plastic. NTM the fact that Apple invented the laptop. It is also fairly easy to have a PC at home, but use a mactop for roaming without compatibility issues nowadays. But then, if you knew enough about macs to know that, you'd probably want a mac desktop anyways
But then they cost a bomb, and cos of their potential longevity, private individuals don't ugrade them so often. And of course, Dell & co will always win the big contracts, cos making the apple switch for a consumer isn't really much of a gamble, other than the surplus expense over an equivalent specced PC; but for a business, it costs much more, especially if it doesn't work out and staff demand that you switch back. Its kind of like a person trying to go to church every sunday for a year to see if it enriches their life versus signing up your entire corporation to a cult that demands big donations, insists you use its specially-approved medical facilities and will cost you a great deal in psychiatric bills if you ever decide its time for everyone to leave.
That said, if the statistics seem modest now, imagine how many new macs and potential switchers we'll be noticing when its 10/15/20%. Eventually, the IT guys, whose livelihood depends on their knowledge of windows, will have to give in and start buying what most of the office wants to use. And by then, Macs should be able to network better in large numbers. Personally, I expect the whole thing to snowball over the coming years, but then there's probably quite a lot of scientologists who feel the same way about their "religion".