I also have my MCP, MCP+I, and MCSE certs in NT 4.0. It was a great starting point for me, because I had spent my professional career in the credit card banking industry, in non-IT positions. I have not pursued any MCSE upgrade courses since then because my position has changed, and I now work with SAP systems, which mostly run on Unix and Linux boxes. My employer is currently talking about putting me through a Linux course, since they would like us to use this with the new systems that we are planning on implementing.
Since you already have several years of experience in IT, I think that it could definitely help you. I would make sure that you focus on certifications that will help to mold your career path. For instance, if you want to work with corporate networks, then you should pursue Cisco certifications. If you want to work in System Administration, then pursue MS certs. Regardless of your area of interest, I would pursue the newest certifications available for those areas.
If you presently don't have any certs, then definitely go for an A+ cert. It's relatively easy to attain, and it will give you a good idea as to what the MS certification exams are like, since they use similar formats.