MeeGo, being a Linux distribution not specifically attached to any devices, can be made to run on many different hardware platforms. Currently, the listings found under Devices are the officially supported platforms. Unlike netbooks, however, handsets tend to have a wider variance in platform capabilities and architecture. Devices like the Nexus One have graphics chipsets for which there are no fully MeeGo compatible (X11) drivers. Others, like older HTC and Nokia devices, run ARMv6 chipsets which are not targeted normally by MeeGo.
If you have a handset that is not listed on the MeeGo Devices page, chances are it will not run as-is. You are always welcome to attempt to run it, however.
If your device is not listed on the Devices page, you may consider attempting to port MeeGo to your device. Many people have taken an initiative on handsets not specifically targeted by MeeGo. For instance, there is a porting effort for the Nokia N8x0 series Internet Tablets. There is also a porting effort for Qualcomm devices such as the Nexus One and Dell Streak. However these efforts are aided in that the Linux kernel has already been ported to these platforms. If there is no kernel support for your platform (either in the MeeGo kernel or via other sources) then porting and running MeeGo will be more difficult.
Porting MeeGo (and possibly the Linux kernel) requires effort and interest. If you are the only person showing interest then it is either up to you to begin the port, or to find someone who is interested as well.
So will MeeGo run on your handset? We don't know. Take advantage of the resources here to see what is possible.