I'm interested to see the breakdown of which VB4 modules users require a migration path for, so have started this poll
I suspect there is more work required for those who have the VB4 suite, where existing blog content would perhaps be migrated to XF threads, and existing CMS content would perhaps be migrated to XF pages.
Whilst I selected the suite, forum only would be an essential IMHO upon Gold or beta release to really garnish sales and conversion numbers to XF. I have one new one I stopped and can quickly convert by hand if necessary, but I have a small one with only basic CMS data and primarily forum data... that I would like to convert immediately. The handful of CMS pages I can convert via copy and paste... literally less than 10 pages. Luckily I don't use the blogs on that one... so if XF launch with a 4.x converter that will strip the forum and user data, I can convert another and simply create a static homepage with forum in a folder. I have two sites I can immediately convert... but only one if a 4.x converter doesn't exist.
One of my own sites, I simply could not convert as the mods and products just don't exist, and I wouldn't risk losing a substantial traffic and user base on making change... so that one will be running VB for some time until the XF infrastructure exists.