|Just another Perl shrine|
Certification is a piece of paper. Some times it will impress someone, sometimes it will not. Sometimes the training behind it is good, and sometimes it is not. Sometimes the exam will be easy, sometimes not. Some certificates are cheap some are expensive. Alas many of these factors are not directly correrlated, the most expensive training, may be very poor, the exam may be hard but the certificate worthless and so on.
I'm not in favour of them per se but those in positions of authority place undue importance on them, because they are too busy or unqualified to make the correct decision based on CV, references and your interview.
If the person making the decision knows what they are doing, I doubt they will have much influence, they will be looking at you and your total skill set. If it's a typical PHB, then it may impress, which could give you the edge you need.
Remember the world is full of MCSEs and most of them are without a clue, finding a good Windows person is very hard.
See also from use Perl: