Yes, BOINC is great platafom, open, blah blah blah. But if we want distributed computing to be a mass-thing (which should be good) we need a simpler thing.
Sure, the new interface is much easier, but if you want an example of really easy distributed computing look at this:

http://www.whaleshark.org/encounters/sharkGrid.jsp

Just load page and click. Done!

So, maybe somebody which actually knows about this can answer: Are there any disadvantages of login-less distributed computing?

For the funny bone:

5. sharkGrid can run in the background (so long as this web page is open) while you perform other tasks on your computer. However, sharkGrid is used for intensive computation, and other applications running on your computer simultaneously with sharkGrid may slow down.

BOINC sciences back off when a user goes to run other apps!

From a security point of view: No, "can't touch this" (MC Hammer).

And Green it aint either, where BOINC has an automated snooze and sleep function:

3. Please disable any power saving features enabled on your computer. For example, many PCs will enter a suspended state (a.k.a. "System standby") after a period of time with no user interaction. Other power saving schemes stop the hard drive, which will also interfere with memory paging used by the Java applet.

Yes, but those are problems of sharkGrid (I must adit that I wouldn't belive it if someone told me that there is a distributed project for shark recognition). Also using a java applet in a web page is not the best way to do it. It was only an example.

I was thinking about an application which you just download and install. Optionally you could select from a list of projects. An advanced interface could also be available for expert people, but normal people shouldn't even notice it's here. It could even come preinstalled with an operating system (in a sandbox).