Realistically? For the next few years I doubt it will make any difference what so ever. Jobs, being well known for his perfectionism has probably already got the cogs moving for the next few years - especially considering this is not a surprising death. Tim Cook, I believe is more than capable of running the company.
In the long run however, it might really start to have an impact. Jobs was an inspirational speaker and a fantastic marketer.
I'm not sure however how much Apple will be able to continue to produce ultra-sleek, ultra-convenient products for, without Jobs' influence and contributions.
Add to that as said above, the growing power of Apple, and Samsung's 'plagiarism,' and you have a real issue for Apple.
Saying that, I really really doubt that Apple being the multi-national conglomorate will be complete powereless, it just might fall down in it's truly revolutionary products - the iPod changed everything. The iPhone changed everything (the newer incarnations certainly didn't 'change everything again'...)
TBH, I would have betted on Apple to produce the first holographic item...
kd