I'd love to use YQL for some major projects, but there are some major and possibly insurmountable concerns.
1: It's a major issue that all YQL queries go through Yahoo. This is a huge developer risk. YQL really should be an open standard that developers can implement for their own sites. 2: Rate limits are a huge issue and again, probably insurmountable issue - it's hard to imagine building serious applications around Yahoo's imposed rate limits - there's so much wrong about this that it's hard to know where to start.
We're set to commence a major project that YQL would have been perfect for but the above problems make it extremely hard to justify, even though YQL solves a real problem and meets a real need.
YQL should not be a Yahoo server technology but should be a standard for any developer to implement.
sorry to reply to my own post but I had some further comments:
That YQL is a middle man between the consumer and provider of the service is another huge issue - latency is a big enough problem for any web app without having to funnel everything via a query to Yahoo first.
That YQL is a middle man service is also a huge risk to scalability.
Finally, YQL makes it clear that the web does have a need for such a standard - the fact that Yahoo has not made it an open standard simply means that other organisations will do the same thing, but as an open standard, which will probably be the end of YQL - a missed opportunity for Yahoo.