Inclined to agree Amazon might garner a substantial lead for Android tablet app distribution, but theres still an awful lot of phones, compared to tablets and I for one cannot see this changing in the short term.
One good thing to note is Android 4.0, is asking for credit card details on initial start up now, so hopefully paid users++ when it comes to the Google Market, which might also help quell the myth of Android users "don't buy apps" which I feel at the moment is self reinforcing by the fact most published apps choose to ad support
Beyond that, Ice Cream Sandwich unifies "phone" and "tablet" apps (a distinction that already makes much less sense in an era with large, 720p "phones"). That completely changes his inferred dynamics of the Android app stores. I think the Android Market and the Amazon Appstore (and GetJar and Handango and ...) and direct sales from developers will happily coexist for the foreseeable future.
The distinction between phone and tablet apps on android has always been pretty blurry, ICS is about unifying the operating system features, not the apps. Talking about a 'tablet app store' is silly, even ignoring ice cream sandwich.
I agree talking about a "tablet app store" is silly (note the quotes around "phone" and "tablet") since many Android apps scale quite nicely for both form factors and more will with time, but, sadly, the Honeycomb detour confused people (especially for iOS-influenced outsiders).
One good thing to note is Android 4.0, is asking for credit card details on initial start up now, so hopefully paid users++ when it comes to the Google Market, which might also help quell the myth of Android users "don't buy apps" which I feel at the moment is self reinforcing by the fact most published apps choose to ad support