It's been very exciting to hear about Yahoo Pipes! I have to admit this is the first time I got impressed by yahoo other than by the cool innovative name at their time.
It feels good personally as well as I predicted this was something that needed to happen in these terms: "Right now it's like we have applications (tables in a simile with relational database world) but we can't link to other applications as we should. To me applications need to grow in the same direction relational databases did." when thinking on the web as a platform last September. I really didn't think much more about it and it's a very pleasing surprise that Yahoo was the company to come up with this.
I'm still thinking that the semantic web is really where we all want to go, and pipes are really just a subset of what could be done with the semantic web. It's hard to understand why we're not moving faster in that direction. I can think of two explanations but not sure which one is the right one if not both:
1. We're not technologically ready, meaning it's too complicated to agree to standards for the semantic web, to find a nice user interface (which yahoo did!), etc.
2. It's not in the industry leaders interest to have a semantic web. This is definitely true for google, but not so true for microsoft, yahoo and others in need of better techniques and market share. I doubt Google doesn't see the potential, I believe it's more about it having the secret search formula to find things in a disorganized web. What would be so unique about google when the web is a semantic place and everything makes sense, nobody will need secret formulas. If this explanation were to be right we'd be saying the industry leaders are not paying any attention to semantic web because they are either challenged by it (google) or they are ADD, unaware of it's potential (microsoft, etc).
The third explanation would be to think that semantic web is not the future web at all, I've seen there are people saying this as well but haven't read much about their points yet.
Anyway, to my current understanding the relational web seems to be one step further until we can reach the semantic web ...