Microsoft is running a huge promotion through the partner channel right now concerning up to 50% savings if you purchase ILM 2007 User CAL's with Software Assurance! The SA rights have been upgraded to include future use of the "added features" in the ILM "2" product. So, if you're betting that the pricing will increase when ILM "2" launches next year then this is a deal you really can't afford to pass up. Even if the pricing stays the same you still make out due to the added discounts and I don't think anyone expects that Microsoft would actually reduce the pricing while adding new functionality!

Now, as for the number of licenses you'll need here it's not entirely clear but there are three ways to approach this from a purely hypothetical perspective:

Purchase a CAL for every identity you plan on managing with the new ILM 2 portal - certainly the safe bet and it fits closely with the way the existing CAL's work for managing certificates with the CLM portal
Purchase a CAL for every identity that will be connecting to the ILM 2 portal for self-service - kind of a twist on "per device", but a bit riskier and no guarantee that this will be acceptable under the terms of the licensing agreement; however for customers interested purely in the password reset realm this would be an attractive option should Microsoft offer it
Purchase a CAL for every object you plan on controlling the lifecycle of - this could get very pricey but given the extensible schema it certainly could go this way; if Microsoft only cares about the identities then this is a big win for people looking to build applications on top of ILM 2 but it could seriously limit adoption if they went this direction
So, don't wait until it's too late or you will be behind by another budget cycle so get moving!

This promotion ends on March 31st, 2009 which is also a good indicator for when ILM "2" may be targeted to ship. If you'd like more information on purchasing the CALs at the discounted rate, contact me directly through the "Email the Author" link below.  For more information on how ILM 2007 is currently licensed check out the Microsoft Identity Lifecycle Manager 2007 How to Buy page.