Beware - Part of this post is way too optimistic
My economic analysis suggests that the economic crises might even help web2.0 startups.
how come? In general investors have many investment opportunities in different risk levels - stocks, bonds, real estate, startups, art and etc...
The investor invests his money according to a risk analysis, % goes here, % goes there and etc... so that he wont risk too much and will still have the opportunity to earn money without risking it too much.
Now that the crises made the stocks, bonds and real estate and riskier investment, the investors can spread their money differently in order to keep the same risk value. so in simple words, startups are now relatively less riskier and more bearable as a long term investment.
And in a more realistic view - The crises probably reduced the pie size, so even if the risk is more bearable, there might not be all that money to invest or to purchase companies...
But all this doesn't matter... as web2.0 sites are not something the economy crises can stop altogether. web2.0 sites were not created because somebody invested money in them, these sites were created because there was a true evolutionary need for them.
Human beings are social and can not survive in a non social environment, the web as we knew it in the era of web1.0 was a non social environment. people used to spend a lot of time with their computer (same as today) but there was no social element to satisfy their primal social needs. this is the reason why web2.0 sites started to evolve, to satisfy these needs.
Web2.0 is "The People", and this is why that even without money web2.0 sites will still exist, there might not be as many sites created every day as today, but they will be created. If the crises will be as horrible as some predict, this will be the opportunity for the students to once again set the tone in the world of web2.0 sites, bringing back the work to the garage, and creating the new big things, just because they had a dream.
This is why web2.0 will never die, well only maybe if we will go back outside socializing like the good old days...