RedHat is still popular...
One think that I was curious about was how RedHat's decision to drop RedHat Linux and force companies to use the pricier RedHat Enterprise Linux was going to fair in the ISP arena.
According to Netcraft, there is a slight market share loss for RedHat, but it is still the most popular of the Linux products for ISP's by far. Of course, the article does not discuss the versions that these providers are using, so it is possible that many companies have ignored the April 30th date. One would hope that they are using the latest and greatest, however, there are some products, such as APC's Powerchute (of which I would recommend apcupsd instead) and various tape vendors that require older Linux versions, so this is not necessarily the case.
Another thing that is not mentioned is whether Fedora is considered as part of the RedHat portion. It is possible that some companies are using Fedora Linux as a server platform, since it is essentially RedHat Linux 10 and beyond.
On the security front, this is a little concerning, however, companies like Progeny provide updates for older versions of RedHat, so hopefully everyone is at least patching...