During college you will come in contact with a broad mixture of people, the likes of which you may never come in contact with again. Why not play the field and keep your options open?
When a lot of people hear the term "play the field" they think of those stereotypical people who go around dating people, hurting them all in the end. This is not the type of thing that you need to do, what this means is not to get too seriously involved with one person. Keep your options open, or rather don't put all of your eggs in one basket. We often limit ourselves and settle for things, assuming that this is as good as it will ever get. Why not make your college years about self discovery, including figuring out what you need from a relationship and what kind of person will make you happy?
This doesn't mean that you won't meet some really interesting people that you want to spend a lot of time with. Chances are you will meet some people that you could consider getting serious with, but don't sell yourself short. Don't assume that this is as good as it will ever get, more importantly don't get tied down to one person or one relationship that does not satisfy your every need. If you do get involved in a relationship and you find that it is not what you need, get out! You have a whole life ahead of you and you don't need to start settling for less than you expect now!
College should be an exciting time where you are meeting as many people and doing as many things as you possibly can. After college life can get serious in a hurry, so take advantage of these years and really experience as much as you can, meet new and interesting people, explore what the world has to offer. There will be time for various levels of commitment and relationships later on. Focus on your studies and when you have time, have a lot of fun.
You should not go away from your college years wishing that you could have dated more or that you should have experimented more. College is the perfect excuse to discover many different types of people and relationships, so take advantage of this excuse and have fun! No regrets after college in terms of dating is a good thing because you'll come out not only with an education but also with a firm idea of what you need from a relationship in the future.