A company fails if its liabilities exceed its assets, and there's no reasonable way the situation can change.
You can always pursue different web 2.0 apps; but it's probably a good idea to spin them off into separate companies.
Imagine a case where you have four projects. One of them really takes off, while the other three are just barely profitable, and you hire someone to help you with the project that's taking off. After six months you decide to let him go. He slaps you with a discrimination lawsuit. Doesn't matter if it's true or not.
If you have incorporated your companies separately, the only company that lawsuit can take down is the one that employed him, because the assets of the other companies can not be used to pay off the liabilities of that company. If you incorporated them all together, that lawsuit can take all of them down. And if you haven't incorporated any of your companies, your assets can be used to pay off that lawsuit.
And the reason it doesn't matter if it's true or not is that, even if you were completely above-board and non-discriminatory, it takes lawyer time to establish that in court, and lawyer time is not cheap.