MCDST is fast becoming outdated and so will be updated to reflect the current OS levels, also the other issue with the MCDST is that it shows you how to go about doing things the Microsoft way and unfortuantly in an industry where SLA is key to the clients, then its no good. As pointed out 99% of the time experience is what is needed, as you need to know the quick way of fixing things instead of the long winded way.
As for the A+ this is a waste of money nowadays, as the A+ is 70% hardware. Which is swapped out on break fix contracts and so the only thing you do is report that the hardware is faulty and needs to be replaced, the N+ however is a great starting point if you want to go towards the network side of things.
What I would sugest though, is watch out for the type of service desk jobs you go for and gain enough informaiton about them before applying. As a hardware service desk is not a very good route to go down, if you want a successfull job in the IT industry. Try looking for more software based service desks, those that are Microsoft and Cisco accredited, especially if they are gold/platinum partners. As these are the type of companys that will invest in your time and invest in you in the long run.
and MCP 
