I don't fully understand why are you mentioning that there will be a
"large" number of web applications . It would be simply one lens
full of links to the user's preferred web applications (actually
websites...) . These can be maybe 10-20 , not thousands . It's
hard to see what is the big novelty here : in 10.04 it is already
possible to create an app launcher that starts firefox with a specific
url.
Hopefully there is no intention to have in the Dash a huge list of all
the websites that exist in the world , right ?!
So the idea would be to have the user's recently accessed websites
presented inside Dash? This sounds handy if done right : if
it's dynamic it would need a clever algorithm for ignoring the
irrelevant urls .