The hardest thing about raising a competitive Pokemon is the hell that you go through in trying to figure out IVs. The existence of stat calculators still requires farming a bunch of Rare Candy or having a useful friend battle you on wi-fi in L100 mode to know what exactly you're dealing with.
The second thing I'd like to see next gen is probably the least likely to happen, but would definitely be useful for the competitive crowd - a way in the interface to ascertain IVs.
There have been baby steps in this regard - Emerald introduced the "IV Guy" at the Battle Frontier who gives you an idea of your Pokemon's relative strength and what the highest one is. Diamond and Pearl introduced characteristics which flag the highest IV and give you a 1/6 chance of guessing that IV, and Platinum has the Hidden Power revealer who can help narrow down the range of IVs (because they would have to equal a particular Hidden Power type).
But next time around, a lot of people would appreciate GameFreak throwing open the proverbial kimono and letting us view them in some fashion. I can think of 3 ways to accomplish this:
1) An in game NPC
The odds for this one are long, but it could be couched in another way. In the city where the Daycare would be, a NPC would be set up who would give the 6 IVs, HP/AT/DF/SA/SD/SP order. If they want to keep the masquerade up, have the NPC say something like "These are your Pokemon's lucky numbers" or have the Footprint guy return and say they're measurements of the Pokemon's feet. Though the latter is highly unlikely given that they'd have to explain Diglett. (In the immortal words of Magnemite, "HE HAS THEM? FEET?")
2) A bar chart
This would be a brand new interface for the series, with six line graphs separated into 32 segments and the last segment reached is the appropriate IV.
3) Contest chart
Similar to the above, except they use a 8 point chart in a hexagonal shape similar to the way the Contest stats are viewable after the Poffins. For those who settle for 28 IVs in most stats, this would be sufficient though a star at the top could be used to represent 31.
The target market doesn't pay attention to this anyway, but it would be nice to throw the competitive gamers a bone like they do - and given that they're running the Video Game Championship two years in a row, clearly someone there gives a flying fadoo about the competitive gamer.