Microsoft might disagree with this simplification, but they seem to have identified two basic market segments: SMB (Small and Mid-sized businesses) and enterprise. In the Enterprise space, Dynamics AX is the ERP system targeted. Licensing for enterprise AX will soon be available through the volume license agreement channel, though the requirements for the partner organization providing licenses in this model will be significantly greater.
The other Dynamics products (NAV and GP primarily, and perhaps SL to a lesser degree), will have a new licensing model. The changes will be good for smaller businesses that need more functionality (like most of our clients).