Im pretty sure that as long as people are being born, there will always be new players to profit from.
Sure the average player base is getting smarter and better, but thats like in many different games and sports. Look at MMA, the mma fighters in the 90's would get demolished by virtually any basic contender now in 2008, they are WAY more well trained, have a better diet, train in not just boxing but jujitsu, wrestling, kickboxing, muai thai, etc etc. Pretty much every fighter that wants to "win" is incredibly well rounded. Just as a poker player should be very well rounded.
People evolve as the knowledge expands and becomes easier to digest and process, the internet is a key factor.
I think the USA plays a key role in online poker, the UIGEA really sliced into the gut of online poker for americans. Once Obama is elected (online poker is doomed if not) hopefully he will establish a proper law for governing online poker, instead of just rendering it null and void. Once this killer has been abolished, you will see a consistant influx of new online poker players.
And by the way its well known from a massive database of
hands that its roughly 30% winners and 70% losers online, in the long run who knows? But in the month by month basis, that is fact.