I think at this stage experience is of more value to you than more studying.
The ideal is to get an employer willing to invest in your training in their time.
You've had two years of experience in IT service delivery, you should have been exposed to various aspects of the field.....so if you've kept your eyes and ears open, what do you see as growth/demand areas and which of these areas can you devote enough time and energy into pursuing to forge a successful career ?
Your next move should be one where you'll get some exposure to enterprise IT practice. But i see some clear trends. And these are areas where you can dip your toe into as they feature in the IT plans of 99% of organisations;
Integrating IT into the building fabric. The idea of Smart building systems.
Virtualization. Doing more with less in a smaller footprint.
VDI computing. Seems impossible to mention this without a nod to blades and
server virtualization products.
Increasing role of Macs in the enterprise. IT's not all bad as you can legitimately call yourself a unix guru.
SANs and Disaster Recovery/Backup operations.....these are major investment areas in large biz and have found their way into the lower end with iSCSI and NAS. Build yourself a cheap NAS filer and understand the protocols.
Ongoing moves towards VoIP and converged communications (think OCS.)
Integration of legacy PBXes with newer VoiP infrastructure. Legacy PBXes seem to be an all pervasive throwback that medium and large business are loathe to ditch.
All-Pervasive impact of MOSS 2007. Being a moss only guy would bore me to distraction (as would any role where your dealing exclusively in M$ currency)
but you can keep it interesting with work that integrates it with other parts of the MS Back office.
Data Center design and Computer room design.
There's loads more such as more traditional roles such as DBA's and AD admins, and ofcourse you can have exposure of the lot throughout your career as a general IT bod but i've picked out ones that i think provide good career prospects and could keep you interested. It is incredibly hard to maintain the various areas of interest when your doing general IT support. Especially as vendors seem determined to offer an ever broader portfolio of products and want to stick aggressively to shorter times between major releases.
What post did you go for?