If every one hopped very few blocks would get solved.
No, if everyone hopped, as soon as a prop. pool doesn't hit a block within 43.5% of difficulty shares, it dies out and either has to close or switch to a payout system that is also fair to miners, not just pool operators.
Unless there is very clearly specified which actions are considered "Pool Hopping" and are being punished, there is no real way to tell even IF I'm currently pool hopping or not for me as a user - especialy since stats are delayed, so I cannot see how far into a round I am for certain.
Another pool (bitcoinpool.com) has a very clear policy outlined what they view as pool hopping and what they are doing about this - I hope the system at deepbit looks similar (not from an architecture view, the one at bitcoinpool can be easily broken - but from a transparency angle).
http://bitcoinpool.com/forum/viewtopic.php?f=1&t=103About PPLNS:
You can make N relative to the current difficulty, the higher N is, the less likely it gets that shares will not be paid anything (Luke-Jr posted somewhere that N=8*diff pays ~99% of all valid shares or so). The "downside" of higher Ns is that the heatup phase until your MH/s rate relative to the pool's rate matches the relative amount of shares in the last N shares gets higher too. The cooldown phase however after you stop mining also takes that long, so it balances out (if you stop mining and N=10*diff, you could still earn on any block during the next ~18 million shares which is ~3-4 hours on deepbit currently).
Solo mining would be the edge case of N=1 share, and the communism/pyramid game approach would be to pay every share ever submitted (N = oo)
If you have any more questions or concerns regarding payout systems, please try to formulate them here or in a seperate thread - often there are misunderstandings, but EVERY system has it's potential downsides/attack vectors (either for miners, operators or both) too. Prop. for example is a system that enables/encourages pool hopping but has 0 risk (actually a lot of benefits!) for the operator, so it's up to the miners to complain.