Actually, that first point ties gnomes to 'margin folk' pretty well.
Not especially. The original question grouped gnomes, avariel, and sea elves as 'margin races,' and I think we can all agree that these creatures actually vary pretty wildly in terms of how marginal they are. Gnomes are pretty common. Avariel are quite rare. Sea Elves perhaps less so than Avariel, but more so than Gnomes unless you're playing an aquatic campaign.
Most likely, we have three independent thoughts in response to three specific questions.
Are gnomes going to get something for PC play other than what's in the MM? Yes, they'll have a racial write-up next year.
How do you guys plan on doing rare races, like the avariel or the seal elves? Don't hold your breath, you won't get much. There might be more stuff online.
Are you going to tie saurials to dragonborn at all in FR? No, these are distinct entities.
This matches what they've said about gnomes ("they'll have a write-up, just not right away"), makes sense in the light of what would see publication (did we see a racial write-up anywhere in 3e for avariel? Or sea elves?), and makes sense in light of what the role of the dragonborn are (they aren't dinosaur-people).
Otherwise, the post would be basically contradicting itself, saying both "gnomes are marginal and marginal races won't see much support," and "gnomes are getting a full write-up in '09"
My money is on gnomes getting a write-up with the Illusionist class, and then not seeing anything for Avariel or Sea Elves (or other semi-obscure subraces) unless we get some sort of aquatic setting or elf-focused setting (more elf-focused than FR), which at least isn't in the immediate plans.