I don't think hp is the only consideration here. The CBR250 scored pretty much a dead heat in comparison tests with the Ninja 250 (the old model, I know) despite being a single with 5-10 less hp. The 250 apparently had a lot more 'meat under the curve' and was less peaky.
I have heard, and do realize, that Kawi has significantly upgraded the Ninja 300 so maybe Honda needs another move up their sleeve with the 250.
If the 500's follow a similar pattern, I don't think that's a bad thing whatsoever. I don't think an entry-level motorcycle rider wants to have to thrash their bike to 12,000 rpm to get everywhere. I'm saying that knowing that the old, outdated Ninja 500 made 60 hp to the CBR500's 45-50.
The Honda 500 section was the busiest of the show when I was there. It's a sweet spot in the market - a bike that can ride 400 series highways and keep up with other bikes on sensible rides, yet is cheap for insurance, in cool colors, for a few grand less than a Gladius, SV650 and FZ6R. I bet they'll sell well.
I bet Suzuki's the real loser here, who will have to do something about their 10-year-old middle-range line-up (Gladius, SV650, GS500, GSX650F).