It’s funny how often discussion seems to revolve around the iPad. Some days it feels like that’s all that I write about. One day last year I stopped in at the butcher store and the first thing out of the owner’s mouth wasn’t “Hello” it was “So what’s the deal with the iPad?” And just yesterday my mom was sharing her first impressions of a friend’s iPad that’s she’s currently borrowing.

Which brings me to my point that following the iPad there’s now RIMM’s PlayBook, the Samsung TAB, and a small avalanche of other tablets coming to market. A category that barely existed a year ago is suddenly getting crowded.

However, don’t start digging a grave for the iPad just yet.

Historically “the iPod killer” and “the iPhone killer” labels haven’t held up well. The Samsung TAB is being hailed the same way as thePlayBook is; yet the battle has yet to be fought.

Despite the clear swipe that RIM co-CEO Mike Lazaridis took during last Fall’s announcement in his comment about being able to view the “full Internet,” a clear reference to Adobe Flash, RIM’s focus on the PlayBook as being enterprise focused is makes it clear that RIM is playing to its strengths as an enterprise solution provider more than as a consumer one.

The initial specifications for the PlayBook are powerful and exciting, but let’s get this out in the open: it’s not the tech specs that make the iPad dominate, it’s the interface. As the tablet category evolves I don’t doubt that we’ll see some blazingly high-powered tablets, and lots of them.

However, the reason why the iPad already has the installed base it has isn’t because the hardware is amazing: except for the capacitive glass, it’s isn’t particularly. The reason is that it is easy to use. Toddlers can use it. The elderly can use it. It’s not designed for computer nerds; it’s designed for everyone else. It’s already been pointed out by me and others that Apple has sold more iPads in the first two quarters of last year than manufacturers in the automation channel have sold touch panels in the entire history of touch panels. The reason why both the iPhone and the iPad have achieved ubiquity as a control system interface is how easy it is for anybody to actually make one work.

In short, it’s not the hardware, because the iPad is virtually naked: it’s the interface. Rival brands that want to build an “iPad Killer” need to get their heads around that.