“On Thursday, before an audience of industry analysts, tech reporters and invited guests, Apple (AAPL) will unfold its long-awaited ‘iPhone software roadmap.’ The event starts at 10 a.m. PT (1 p.m. ET),” Philip Elmer-DeWitt blogs for Fortune.

Beyond covering what we know from the invitation and recent comments by Apple execs, Elmer-DeWitt summarizes what’s rumored, including:

• The SDK runs only on Macs running OS X Leopard and is facilitated through an enhanced version of XCode made available to members of Apple Developer Connection.
• iPhone applications will be allowed to use both EDGE and WiFi for data.
• That Apple will have the final say on which commercial iPhone applications are sold, will distribute them through iTunes, and will take a small cut of the proceeds.
• That iPhone freeware is unlikely to be subject to much if any scrutiny by Apple.
• That this SDK will not support applications that access peripherals through the iPhone dock connector.
• That the final version will be released at the World Wide Developers Conference in June.
• That there’ll be lots of demonstrations of business applications from the likes of IBM, Salesforce and Microsoft. (We’ve already been contacted for pre-SDK coverage from several firms that make apps for business, including SAP.)

More info and links in the full article here.