As to whether or not that matters depends on how much the community depends on functionality provided by things that habe teh potential to be broken by simple OS upgrades.

I’ve had many an app crash my Windows or Mac at home. I’m not about to ditch those OSes because some apps weren’t tested properly.

The Pre has an app store. Most people will do all of their app shopping there and never know about external sources,hacks, etc. You want bleeding edge stuff, you know you have to deal with possible instability.

1) The hackability of the Pre is a strength, rather than a weakness. Developer interest is only attained by letting developers hack the device to the greatest extent possible.

2) More powerful apps are developed when you let the developers deeper into the OS. One of the strengths of PalmOS was that a developer could get into things like the calendar and the file system functions.

3) The Apple App Store has the approval process (mostly) to prevent applications which would hurt AT&T or Apple’s income — not to improve stability. Case in point: Copy and paste. Apple specifically crippled the SDK rules to prevent people from writing apps that do background processing or interact with other apps. Why? Not for stability reasons, but so that Apple could then implement such solutions, and sell them to consumers (in the case of iPod Touch users, at least).

4) The Pre is based on Linux, so Palm doesn’t have much of a choice in the matter. They’ve got to release the code. Once they’ve done that, the hacking is inevitable. Better to bow to it.

And lastly…

5) This gives Palm thousands of people to develop apps for the Pre, right out of the gate, not to mention all the Linux apps that will certainly be ported to the Pre.

Are there security concerns? Of course. A person has to be careful what they install on their system, whether it’s a desktop or a phone. But in this case, the rewards almost certainly outweigh the risks.