We regularly advertise for perl programmers. We get about 40-50 responses. 30 of these have little or no perl experience (some don't even list perl on their resumes, others say things like PEARL). For my part, a basic certification would say "Ok, you know how to use modules, how to write modules and the basic concepts of OOP, great -- you get through to the 'seriously consider' pile."
In terms of degrees, I definitely concur with the comments made by others -- unfinished degrees don't speak well for your longivity/tenacity/commitment to finish things you start -- which after work ethic and team skills, is probably the next most important skill for an employee. And whilst a degree helps you learn how to think, I think the best thing a degree gives you is what you learnt *outside* the classroom, when you were hacking code in the labs with your mates. Friendships, shared experience and rapid learning about new stuff.