Ubuntu 10.04 will be a LTS (long term support) release with 2.6.32 kernel and so it would make sense to make OpenVZ patches for that kernel version.
I think the reason why people don't want to go from 2.6.27 back to 2.6.18-rhel is because they think going to older kernels is a bad thing, so it's mostly psychological. There are some valid reasons too, like driver support if you have a newer hardware.
It would be much better to have supported OpenVZ patches follow Ubuntu release schedule (every 6 months) than RHEL with a schedule of several years. Linux is constantly evolving and you simply cannot afford to stay behind.
It would be great for OpenVZ to have good public relations. As it is, it takes months to get any info from the developers, there are no real news about the new developments or anything. All that users can do is sit, wait and wonder. Not enough communication is the reason why rumors start, which more often than not, are false and only hurt your product.