No, you can still rename interfaces using udev just like you can now. This is largely about ensuring that devices get predictable name at install time. As is pointed out in the LWN comment thread, for anyone who has to provision large number of servers with multiple NICs that connect to different networks this is a godsend.
Why not give an argument to the kernel to create the new devices as "fooX" (foo being a supplied parameter) - and let udev userland deal with the renaming to "ethY" as it pleases ?
While this novelty certainly may appeal to the folks who are used to alphabet soup in the network adapters list, and I too think that the adapters that distinguish between the T568A and T568B cable layout have a degree of coolness in them by creating an extra value in being able to distinguish between the straight and crossover cables - overall it seems like a step back to me.
I would plug in the interfaces into a switch - and all I care is to find the same MAC address as I see on the switchports - not which bus they attach to.
Ability to rename: http://lists.us.dell.com/pipermail/linux-poweredge/2010-Nove...
Why the eth prefix can't be used: http://lists.us.dell.com/pipermail/linux-desktops/2011-Febru...
More background: http://domsch.com/blog/?p=455