In todays computer systems the main bottleneck is not CPU but disk access which is several orders of magnitude slower than CPU and memory. In such circumstances the way to improve application performance is to prefetch data it needs from disk before it even requests it and it is the point of prefetching techniques. This speeds up boot and decreases the time needed to start programs. This replaces and it is faster than the currently used readahead.

Ubuntu is the name chosen for a global project and a distro based on Gnome. Kubuntu is another distro based on kde from the very same project.
I believe they deserve the same support from the project since Gnome and Kde are the most popular desktop manager out there.
It seems quite obvious to me, the project is very much focused on one and only distro, its first baby : ubuntu.
And it shows. Kubuntu web site looks quite poor and unprofessional compared to ubuntu. Most graphic choices like the kdm default theme (even if it's supposed to be a matter of taste) look, again, unprofessional. And finally the whole distro doesn't seem to have the same amount of attention when it comes to details (one example among others: the little thing on ubuntu warning the user about the existence of proprietary drivers for display which does not exist on kubuntu).
I've been told once, like a year ago, by an ubuntu dev that the situation is such because the project doesn't feel like fragmenting its market share.
Whatever is the official position of the project, I don't think you should do things half way.
The Kde project is itself in full evolution with Kde 4. It does deserve full support from ubuntu.

Thank you for reading.

Some of the newest laptop like the HP dv6000, doesn't have WLAN support cause of the BCMX43 driver.

Ubuntu has some simple yet fun games on the LiveCD, but we're missing this feature on Kubuntu's LiveCD. I realize this is no big priority, but it's probably not too difficult to implement either. 10 minutes while installing Kubuntu may not be enough to figure out how to connect to a WiFi, but it sure is an appropriate time to play a game of KSudoku or KPoker or anything from the kde-games package.