Great question. I'm playing a wizard/beguiler/UltMag PC right now.
It doesn't mean you couldn't build a normal metamagic stack once you gain high enough spell levels. This is a quite useful class for that purpose...keep grabbing those metamagic feats since you can uberpower Augment your spells early on with just one feat (Quickened Wall of Force FTW!), and later on you stack the same metamagic effects per normal casting.
I don't recall if it specifies that you cannot use metamagic rods with augmented spells...my group has a gentlemen's agreement that it cannot.