Let me add that again, this goes to show that depending on a vendor for an important technology in your startup can actually be risky. Using open standards are always the way to go.
Well, no. Certainly not "always". You're absolutely right about the big risk, but sometimes the reward is worth the risk. Selling Photoshop plugins means being dependent on Adobe's decisions, but that doesn't mean you should go into business selling Gimp plugins instead.
What you have to do is keep the risk firmly in mind, and hedge it. Pay your insurance premiums.