It looks to me like the iphone sdk roadmap might actually have been released... in the invitation.
Looking closely at the map, it appears to have three parts.
1.) Software Update- Could this be the 1.14 update we saw yesterday preparing the road for the sdk?
2.) SDK- The March 6 event?
3.) Enterprise- Then enterprise users (apparently the main focus of the upcoming event, which makes sense because the biggest hurdle to market penetration for the iphone is that it can't compare to the Treo and Blackberry when it comes to enterprise integration, yet) will get to intergrate it with their systems.
I seems like a plausible, if simplistic roadmap, but hey, this is macrumors. Perhaps the roadmap goes in the other direction, with enterprise users getting it first, then releasing the SDK, then people getting new software, but with yesterday's update, I doubt it.
All in all, I'm excited about March 6. Luckily March 4 is exciting (mini-super tuesday), so that'll tide me over.