This is not a reason for preventing 3rd party applications or releasing SDK
I'm sure that many people misunderstand the technical issues at play when changing a processor so let me explain this for everyone at a very "user" level:
1.) Processors run Machine Code, Programmers write in c, c++ or ASM, Programmers then compile programs from these higher level languages (easier to read than machine code) into machine code using software called "a compiler"
2.) Releasing these applications for Intel chip when written for ARM is no more difficult than recompiling for the new chips.
3.) SDK would not change, only the compiler would change... that will have to be provided by Apple (though the 3rd party area can and will do it).
4.) Many people who already own iPhone are not going to buy a new one and so all applications which Apple provides are going to have to be compiled by them for not only ARM but also the newer Intel.
Basically to close, this is all just rumor so far. Apple is not expected to support 3rd party applications. The developers of 3rd party applications will continue to update and support their programs for as long as they are able to write them for the iPhone. Apple suggesting or this author inferring that this is the reason/justification for not allowing 3rd party applications or releasing an SDK is total ... well for lack of a better word that will make it through the censorship, BUNK.