I'd say it totally depends on what sort of applications you use and what are your and the applications' general requirements..
For a regular student taking a technology stream, I see Office packages, and a platform running a few virtual machines as mandatory these days. And IDEs like netbeans/Eclipse. So I suggest for nothing less than a laptop with a 6+ gig of Memory and a dual core processor (if not quad ). Wear and tear comes as a package with the student life so spending some hefty money would not make much sense, rather go with high specs on regular brands.
Smartphones these day have become sort of a part of your life, if you feel email/browser/rss readers/social media and IMs are something you need on the go they are for you. There are low spec cheaper android phones on the market.