There is some question about which devices occur on your laptop. Please type "lspci" from a root shell and post the results.
The website http://www.linux-on-laptops.com
is alwas a good starting point (and www.google.com/linux
the best search engine).
This guy http://mikey.com/mikey/personalinfo/...ron_1405E.html
says his dell 1405e has an Intel3945 wireless (but I guess you have the optional 802.11N) , and a 950GM. YMMV.
Here is a thread of someone getting this wireless up on Ubuntu. http://ubuntuforums.org/showthread.php?t=342558
You can do the same on FC6, but use "yum install kernel-devel" instead of the apt-get command. Many people here (not me) are familia with ndiswrapper.
I think your wired network (bcm440x) should be handled by the b44.ko driver that comes with FCn.
Does "lsmod | grep b44" show anything ? If not type "modprobe b44
Does "ifconfig -a" show any interfaces ?
Are there any messages in "dmesg | less" what indicat ehte driver failed ?
I'd suggest you remove the XEN kernels and use the non-virtualized ones unless you are urgently trying to use the virtualization. The reason is that I believe that XEN project on Linux is going away - the kernel based KVM appears in the 2.6.20 and appears much better on the surface.