Originally Posted by d-range
Incompatibilities may not be the right word for it, but I couldn't come up with something better. What I meant is that all the alternative Android app stores have a different selection of applications, different payment options and different ways of installing and and updating applications. For many users this is inconvenient, confusing and not user-friendly. This is not even considering how well some of these app stores will be supported by the manufacturer, now and in the future (I'm thinking about stuff like the Archos AppsLib and such).
A user would still have to choose to install those stores...or buy a device with it pre-installed alternative store (Kindle Fire). From the stores I've used installing an app is as easy as it's always been...and payment options are usually tied to either a paypal, an amazon account, google checkout/wallet or in some cases your carrier.
It's not that confusing...hell, it's not confusing at all.
I basically made the same point. I'm not against being able to install stuff from alternative sources, but it's not something everyone should be doing without considering the possible security implications. Which basically almost puts installing APK's from untrusted sources into the same category as jailbreaking an iPhone and using Cydia.
A user has to choose to enable this option...and it gives fair warning into what you're possibly allowing to happen.