The only MS Press book for SCCM is the SCCM Administrators Companion, ISBN 13 978-0-7356-2385-9. As far as CBT's go, CBT Nuggets have something out for it but I haven't found any practice exams (I have tried SelfTestSoftware\Transcender and Boson).
There are a couple of books on SCOM from other publishers but nothing from MSPress at all.
I am actually due on the M6451 course the week after next (SCCM), I am new to the whole SMS\SCCM environment but I have been playing with SCCM for a few months now (I have installed it onto 2008 server which is more difficult apparently) and it's working, I am hoping to pick up enough knowledge to do the 70-401 exam soon after the course (it depends if I can find out what makes up the exam, I may even take it on the Friday after the course if I find out more info about it).
As it stands SCCM is huge but I am really enjoying the whole new tech challange and it's kinda kick started me on getting my updated certs done.
There are a few places you should start looking at for more info,
and the technet forums, lots of information there about all sorts.
SimonD.
The real world is not about exam scores, it's about ability.