What seems to be the latest idea expressed by Linus and carried by other kernel developers would involve bumping the kernel version to Linux 3.0 for the next release (what would have been Linux 2.6.40 or some other release in the near future) and then succeeding kernel releases would be tagged as Linux 3.1, 3.2, 3.3, etc. The third version number (e.g. Linux 3.0.1) would denote the stable point release. The versions wouldn't consist of both even and odd numbers.
Obviously then at some point in the future it will raise the question about bumping to be the Linux 4.0 kernel. Linus already notes in a few years time he'd probably look at declaring the Linux 4.0 kernel around the time of Linux 3.40, but this "Linux 3" isn't simply to denote the Linux kernel now entering its third decade of development.
There's some still interested though in having the Linux kernel version be date/time oriented, like was proposed by Greg KH in 2008, but he's on board with any change, including this Linux kernel 3.x naming proposal.
Some developers and users also don't see a need to change from the current Linux 2.6.xx versioning, but overall there's more people that seem positive about the effort this time around. With the blessing of Linus, this is likely to take place.
There's also some that would have liked to see the Linux kernel versioning change upon the BKL (Big Kernel Lock) having been removed, but that's already after the fact now (that milestone was hit in Linux 2.6.37). Another developer has proposed that Linux 3.0 not be tagged until the ARM architecture code has been cleaned-up, but so far that proposal doesn't have any following.
There's even now some developers submitting their merge window pull requests as being for Linux v3.0-rc1 (example) in hopes of this fundamental change going through and being done for this 2.6.40 development cycle that's already under-way.
We'll keep monitoring the highly-active mailing list to see what is reached... This is also really great timing because, errr, just wait and see. ;)