I wouldn't be so sure on not seeing much Starter.
Microsoft needs the Starter edition to sell to Netbook manufacturers at a price point they'll accept, which is already more than supported Desktop Linux distributions cost (from say Canonical or Xandros).
The specs of Netbooks are at the moment restricted by the discounted-XP licensing arrangements from Microsoft (single core Atom processor, 1GB ram, certain size screen.. etc..).
Those restrictions can't stay in effect indefinately and what with the pace of semiconductor development, we'll see dual-core processors with a couple of gigs of ram inside the same price/power ratios we've used to with the current generation of Netbooks.
It's really lose-lose for Microsoft in terms of Netbooks not cannibalising their existing notebook OS profit.
They can't charge more than the $15 or so they're currently charging for XP, for Windows 7. OEMs are gaining more experience with integrating Linux with their hardware and they'll use this as leverage.
They can't restrict the specs of machines for much longer, or you'll be able to buy a low-spec Netbook running XP or a far faster Linux-based one for essentially the same price. Not a good outcome either.
If they don't restrict the specs, they need to restrict the software and hope they can convert the customers up to a more expensive version of Windows.
I personally think the last strategy, despite potentially playing in to Google and Linux's hands, is their best one. The outlook really doesn't look good though.