There are also interesting efforts outside the “Spectra world” 😉 on mashups. Particularly, I like Mozilla Ubiquity because of two aspects: putting the user in control with a client-side approach and the interaction experiences. It is a very young project, but very promising. Just look at the prototypes and enjoy:
If you want to dream on the futre Web 3.0 a little bit, look at the Aurora Concept Video:
Aurora (complete video without commentary) from Adaptive Path on Vimeo.
Cool! Isn't it? 😀