If it's somewhere you intend to stay for a while, i could see staying away. But if it's your standard retail gig, go for it. One of you probably won't be there in a few months anyway.
If "at work" means "in the same area/group as you," so that you'll be working alongside them--no.
If "at work" means in another department/building/division altogether--it happens at my company (2,000+ employees) all the time, and marriages between employees are sometimes announced in the company newsletter. The official company policy holds that if you start dating a co-worker in the same group, then you have to notify your supervisor so that one of you can be transferred somewhere else. Otherwise, it's A-OK.
Yeah, look at the corporate policy in your employee handbook, first. If you work with this person on a daily basis, I'd highly go against it because no matter what you guys may agree on, the relationship will play a factor in your professional life.
I choose not to get involved because I leave nothing to chance, if I'm not getting a promotion, or worse, get fired, it better be for my performance, and nothing else.
