As a .Net developer I always dreamed for the possibility to develop with my existing skills (c#) applications for the Iphone.
Both programs require a Mac and the Iph
These are fun and interesting ways you can build iPhone apps. But, for truly rapid native iPhone development, your best bet is the free iPhone SDK and Xcode.
To be honest, the hardest things to learn are the capabilities of the frameworks themselves, NOT the language syntax. But that is an issue you have to tackle either way as these IDEs/Languages still require you to grasp some of the conventions of Cocoa (and Cocoa Touch).
I don't say this as a Cocoa / Objective-C snob, but if you know C (which as a C# dev you do) there really isn't any barrier to entry.
In addition, you will have access to tons of tutorials and sample code that just won't be available for these fledgling translators/IDEs/languages.
Learning another programming language is rarely a bad thing, and as an experienced programmer, your time investment won't be as large as you think.