What do you think is going to happen with the stock, product development, general philosophy of the company due to his retirement. If you haven't yet heard about his resignation you can read more here, Steve Jobs Resigns. Also do you guys think that health was the leading factor in this decision or more of a combination of health and additional reasons?

I think the stock will suffer in the short term, but should stabilize and bounce back as long as the street knows the direction of the company is in good hands. Hopefully the succession and transition plans will take care of too much bumpiness down the road.

With iPhone 5 coming to Sprint, apparently, in October, I think there are bright spots on the horizon.

Jobs will be greatly missed but his clock was running and future performance probably would not be up to what he did during the last 20 years. That and health cause most all of us to "slow down" with age and we should consider leaving while still standing tall. Stocks, will be down but not a huge hit.

Well as he has been on medical leave since Jan, this was hardly a surprising move.
The man has serious health issues and needs time for himself.

I think he's done the right thing and made a very bold discussion.
As for the markets, hey they'll recover.

Remember he isn't completely leaving Apple, but moving aside for someone more capable to take the reins, while he oversees from the Chairman's role..

Good luck to him and I truly hope his health issues stabilise.

Short term: Stock prices take a hit but I do not see this as being a huge hit less than 20% and considering their stock price run up and cash reserves the resignation of Jobs is not their problem.
Long term: Most of their sales are now in mobile and Android has a larger install base and a larger developer base. This is reason for concern. iTunes is a huge cash cow the largest music retailer in the world wit a large cash flow. I see the closed nature of their mobile and PC platforms as their biggest threat as well as an asset. I beleve their star will fall as other platforms mature and gain a larger group of supporting services this has to be a windfall for Google now that they are getting into social, music and they have Android.