The offer page says:
Purchase a new user license or an upgrade license for IntelliJ IDEA 5.1 now - and benefit from our special offer. When version 6.0 comes out in early autumn, you will get an upgrade for free, plus one user license for the new JetBrains product - TeamCity.
What does a "User License" mean? Is this instead of/in addition to a server license? Is this required for IDE integration/delayed commit/etc? Do you need a license per user login? Does this affect guest login?
I don't want to end up with a less useful tool than CruiseControl due to licensing issues (we will likely have a mixed environment of IDEA 4.x, 5.x and 6.x licenses for at least some time and though I'm okay with the older versions not being able to access some of the more advanced features, if they can't view the build status without a separately purchased license, then TC may be a no-go for us).
I guess I should send this to sales, also.