As much as I wish for Steve's continued health, I feel that Apple PR (and Jobs himself) has handled this entire issue terribly. They can issue statements of denial until they're blue in the face, but they mean absolutely nothing until we hear an official comment from Steve himself.
So, that said, why doesn't he pen another open letter? It would serve to assuage the fears of both Apple shareholders and the technology community, while at the same time earn him a little goodwill that was lost when the whole "he concealed his pancreatic cancer for nine months" thing came to light. Either he'll have a new health issue to share (and it sounds like he does), or he'll put the fears of many to rest for quite a while. Either way it's a win-win for Apple: if he's ill again, at least they're disclosing it; if he's not, so much the better.
The entire world of Apple is based on a culture of deep secrecy. However, as the most valuable man in the consumer electronics industry, Jobs' right to healthcare privacy is, IMHO, essentially nonexistent. Though they don't have a legal responsibility to do any of the things I've suggested, the company can't afford to be anything less than completely transparent in this case. The fact that they have not been, and the fact that there hasn't been widespread outrage because of this, boggles the mind.