Is this a trick question in this post NSA-Snowden world? Smiley Obviously this project is far from replacing google now. Short term, mid term.
First of all I could not believe I have never heard of this project. So maybe before making another parallel project like this one with the blockchain you could contact the dude behind YaCy and ask to help out anyway you could?
But YES I would do my best to help out by maybe be a simple node on the network or use YaCyPi. This search engine is something a lot of bitcoiners would love to use, the more the merrier on a peer to peer network obviously...
I think that to a degree, YaCy has features of the bitcoin technolgy, both are decentralized. So I do not know directly the benefits of having it on blockchain technology.
To interact on the client side from code is very easy :
http://search.yacy.de/yacysearch.rss?query=Bitcoin&maximumRecords=10 (RSS)
http://search.yacy.de/yacysearch.json?query=Bitcoin&maximumRecords=10 (JSON)
As you said, its not near replacing google now. Sure, you can get a bunch of results but you want these results are accurate to your query. Given enough data, you could organise the results in a way they fit the query on client side. The main problem is the search results relevancy, the interface (I prefer more simple interface) and the domain name.
These are all problems that can be addressed.
For example, the relavance could be improved using this algorithm:
Anyway the topic is about net neutrality;