Two bits:
With Safari for Windows now available, you poor folks marooned on Windows no longer have any excuse. Pick Firefox or Safari, but for God’s sake quit using IE.
Webkit development on the iPhone doesn’t mollify us. It sounds like a pretty poor way to do “real” apps, like a hypothetical replacement email client, an SSH tool, etc. We’re still pretty happy we didn’t wait.
We’re really excited about Leopard, but October seems like a long time to wait.
More: Gizmodo has a long writeup on why the iPhone will be crippled by the lack of an SDK. It’s spot on.