Here's how I see it, I think pokemon can keep creating Generation after Generation as long as a few things happen
1. They must create ORIGINAL ideas for new pokemon, original designs, ect. This also means they have to be careful with what they decide to base a pokemon off of, as it looks like they are moving away from animal like creatures, to more electronic items, or remakes of the past(like the ongoing set of bird pokemon.) Though I do believe they can get away with the pokemon with "god-like" powers.
2. The TCG must stay popular. How they plan to do that? I really don't know, but I'd be careful, throughout this whole Diamond and Pearl, Platinum, and HeartGold&SoulSilver sets, we saw the game go from synergy, and strategy, to a more of, who can set up fastest and start killing first? This has changed the game to a long interesting battle, to a quick battle, which could shoo players away, I've seen it happen, and I think Pokemon should be careful on how cheap the cards they make are.
3. The video game must stay popular. Not competitive kind of way, since that's the only reason the TCG is popular these days, but more of publicly. Every time a new pokemon series comes out, more people buy the game. But could their come a point where people stop, because the series ran to long, or the designs are ORIGINAL anymore? The moment this happens, is when Pokemon's empire falls.
Overall, I can see future generations to come, many, for a long time, as long as the 3 things stated above are correct, and they can become even more popular than before, with the amount of fans joining everyday, and maybe something like this could happen...
The Pokemon anime could be better HERE. I'm not worried about it's popularity in Japan, but, it's not the most popular thing here.
That's all I got to say about this. I can't wait to see Pokemon's hopefully bright future.