I got some pain in my finger after playing Diablo2 for a number of days non-stop.. 
I've a gel-thing for my keyboard tho .. anyway.. RSI=offtopic
applications are also RSI makers .. yay for hotkeys, to avoid using the mouse 24/7 24 days, 7 hours a day? 
24 days, 7 hours a day?
Wouldn't be the first time for me to skip a night in order to make a deadline
Mice are not evil RSI makers. People are. If you take a break once in a while, make sure you're sitting in the right position, your desk is at the right height, your arms are horizontally with your desk and your're looking straight at the top of your monitor when holding your head straight, then you can safely use your mouse. Abuse leads to physical complaints.
Yeah, but really, how much fun is it if you have to be conscious about such things all the time?! 
I'm using computers for more than 20 years now. I've sat in every strange position possible behind a computer screen, I've been using a mouse for more than a decade. At my work, I work with a PC 8 hours a day, when I get home, I add another 3 hours behind the computer and I never ever experienced things like RSI. Guess I'm lucky. And indeed, I don't think about it at all and I'm certainly not going to.
Mice are not evil RSI makers. People are. If you take a break once in a while, make sure you're sitting in the right position, your desk is at the right height, your arms are horizontally with your desk and your're looking straight at the top of your monitor when holding your head straight, then you can safely use your mouse. Abuse leads to physical complaints.
Oh and, on topic, this machine is way too much a game machine. A 'new' MSX should be what MSX has always been: a machine on which you can be creative. So it should at least have a keyboard and it must be fairly easy to develop things for.
ahum, at work i sit straight. my arms rest on the desk. i have had lessons in "ergonomic (english word??) using of computers" and i obey it. But it really is the goddamn mouse that hurts those tiny muscles in my hand and arm.
on topic: i agree with you here i would like to see a new gamemachine and thre MUST MUST MUST be a keyboard indeed! and not a tiny (cellphone size) keyboard that wastes my little muscles but a kingsize keyboard where i can slam on.
Oh, and it obviously needs the [SELECT], and [GRAPH] keys furthermore, i wouldnt like to see PC keyboard like cursors. where there are 3 on a row. dont like it
EDIT:
during my MSX times (without mouse) i sat in the most weirdest positions, but never had any pain. i slowly progressed when i started using mice
EDIT:
more ontopic after reading legacy's post...
but then it aint portable anymore. i would be nice, but i prefer a good machine above portabillity. how about a portable version and a "desktop" version.
I'd say this would do nicely as an optional MSX. You know, you have the real thing at home, where you can work on and do things like typewriting (TED, yay! 
), and the PSP-sized one for during train trips. Can you at least play 'The Fairlyland Story', on the road! (Damn, that game didn't came through during the previous megapoll... Ah well, can't have it all, I guess 
)
Oh, and it obviously needs the [SELECT], and [GRAPH] keys furthermore, i wouldnt like to see PC keyboard like cursors. where there are 3 on a row. dont like it
Yeah! You rule, DarQ. After all, slammin' on a keyboard isn't a sin It's most likely the cheapest part of the entire machine.
[D-'Pops mouse from its port and throws it around in his mess'-Tail]