IMHO that is one of the good thing about android. You can sideload just about anything. ESPECIALLY if you are rooted and have an unlocked bootloader. tbh most devices already have the bootloader unlocked and the few that dont have it have community cracks for it. My tablet was locked and holy crap, now its unlocked thanks to the dev community haha. the dev community for android is HUGE. just about every flaw with android has a rememdy that the dev community cooks up and shares. like UA mentioned, www.xda-developers.com is the place to go for anything android.

@ima- the fragmentation of android is indeed a problem which is why ics or android 4.0 is such a big deal. its supposed to unify tablets and phones and keep 1 os instead of having a bunch of different os's on different devices. its a bit of a double edged sword imo. everyone gets a different experience which is great but sometimes its not a good experience. android needs more consistency. but it is awesome that i can put so many different roms on my phone or tablet and change the things i dont like or have a new experience with it. wanna overclock? just flash a new kernel and overclock to your hearts content. wanna oc even higher? run a script with higher voltages. want better battery life? flash a sbc kernel and run a script for under voltaging. why not mix and match them? free wifi hotspot and tethering? yes please. want the new os before anyone else gets the ota update? yes please, ill take that. wanna tweak the crap out of your phone and make it run like a brand new one? sure ill do that. wanna completely change the way your os looks inside and out? done. even if honeycomb seems old already (which i dont think it does) you can change EVERYTHING about it. and its all open source. why do you think so many devs flock to it? its easy to manipulate, its free to manipulate, and its fun to manipulate.

i hate sounding like a fandroid too much haha. win7 mobile and ios are great os's but nothing comes close to the amount of deep ui and performance tweaking that android offers. let me put it in an easy way: if you dont give a crap about making the expierence your own and just want something that works for your basic tasks, then stick with win7 or ios. otherwise, android IS for you.

the hp touchpad can be found for pretty cheap and the ics rom is coming along pretty nicely. BUT...its just like anything else man, its still in beta and its not rock solid yet. its still a bit of a gamble if you wanna go that route. i would do it because i get nerdgasms over this stuff and the development is going pretty fast. check into it first to see what the bugs are right now. otherwise, for the price its a great tablet.
*looks like its still in alpha.
http://forum.xda-developers.com/forumdisplay.php?f=1247

acer iconia a500, asus transformer, galaxy tab (the latest one) can all be had for about $250-300 on newegg. the acer and galaxy both have 8.9" versions available.

sorry for the long post