I'm playing a gnome. He's identically slow in relation to all other gnomes, because the numbers say he is. The justification for this is largely irrelevant to me, but I willfully suspend disbelief so many times per second while gaming that it's just one more drop in the bucket. Because...well, he's not only slower than a fat asthmatic peg-legged human, but he can also speak seven imaginary languages, intimidate giants, and kill people with his mind.
I from what I've seen of Next, it seems like a lot of the changes are intended to simplify the experience, on a variety of levels.In my view, that's a grand and worthy goal, both from a business perspective, and as a player. Even 3.5 was, lets face it, intimidatingly complex and confusing for a new player. Most of my gaming experience was in 2e...which I understood well. Then a few years later I landed in a 3.5 game and it took me three hours to make a character.
Fast forward now to Pathfinder many years later, and I find myself with a multiclass character so complex that I have to program spreadsheets and build 20 page word docs full of notes just to keep track of what my character can do, what he'll be able to do next, and what I wanted him to be able to do five levels from now.
If I left it until it was time to level up to figure out his level progression, our gaming group would never get any time to gain XP, the gold-standard for "realistic" gaming mechanisms (he said with eyes a'rolling).
The complexity issue is largely self inflicted, of course, both by the developers (in the quest for eternal revenue), and by the players (in our quest for bright shiny new things, larger numbers, and fabulous loot).
Honestly, I won't be giving any more of my money to WoTC regardless of the specifics of Next, because my group is already heavily invested (financially and mentally) in Pathfinder. But, that being said, if Pathfinder went ahead and and equalized all PC movement rates tomorrow it wouldn't bother me in the slightest. Not because I want a faster gnome (I'll have one soon anyway, he's a monk) or because I think short imaginary critters should be as fast as tall imaginary critters, but because trying to assert realism in regards to individual character abilities within a game system like this is an exercise in diminishing fun returns.
Yes, stat-based movement speeds would be more realistic. So would encumbrance rules. So would distinguishing between the movement, balance, combat and tumbling effects of wearing 60 pounds of plate armor, or carrying 60 pounds of enchanted bananas in a sack in one hand, while casting magic missile on a tight-rope, and drunk. And how fast can I move with only one shoe, a migraine, while wearing a rucksack with an angry shadow mastiff stuffed headfirst into it?
So to wind down the ramble; for this player (and erstwhile DM), all the books and rules, modifiers and calculations, are just a means to an end...and that end is not a reality simulation. The systems will never be perfect. When the developers make a change you don't like, just ignore it, or change it back, or paint it purple, stick horns on it, and turn it into something shiny for your players. The rules in the books will never reflect reality as accurately as they might.
But that's the point of playing these games, isn't it? Creativity, flexibility, and most importantly, in my opinion, storytelling. If the rules were a perfect reflection of reality, we'd all end up sitting down together on a Saturday night to eat pizza and itemize our tax returns. Unless there's a prestige class for actuaries in the upcoming Low-Risk Indoor Respectable Professions of Faerun sourcebook, I don't think (m)any of us really want to do that.
If I have to count beans, they'd better damn well be magic ones.