Linux 2.6 and LiS 2.18 vs 2.16.18

Hi there,

though listening to this list it seems unclear to me which way to go 
when migrating from Linux 2.4 to 2.6. We use the inet driver and the 
timod/xnet library currently from 2.16.18 (openss7). Now I'd like to 
start a discussion about the future way (2.6 kernel). The alternatives 
are first using 2.18 + ported inet + timod  or second porting 2.16.18 to 
support the 2.6 kernel. However there are questions left:

Are there people supporting/maintaining 2.18 in the future?
Is it viable to have both 2.4 and 2.6 support in the 2.16.18 sources at 
the same time?
How easy can drivers/modules be ported from 2.16.18 to 2.18?

I'd like to hear your opinion. Hopefully there is a lot of response, 
maybe even a big discussion on that topic.

Regards

Christian