Windows XP and Server 2003 logos in the DTM

A hot topic of discussion today was support for Windows XP and Server 2003 logo testing in the WDK.  I actually had slides on this in the presentation I used, but I pulled them because I figured driver developers wouldn't really care.  Anyway, we are going to retire the HCT when the WDK RTMs.  We're doing a lot of effort to ensure the DTM can do logo testing for those down-level operating systems.  There will likely, however, be an overlap period where customers will need to use both the HCT for XP and 2003 and the DTM for Vista.  What would really help me is some real data on what the impact of that will be on you.  I want to minimize the impact, but first I have to quantify what it is.  If you can help, please let me know.  I just need a good idea what the impact of having to support two logo tools would be on you.