What happens is my IP gets blocked by YC. So until the traffic dies down or I change my IP address, it errors out while getting the comments (YC serves me a blank page).

That issue is actually why I went with a distributed approach to news:yc. Yeah, it's a pain: no remote updates (App Store restrictions) and a lengthy review process for each change needed (do you know about how often the markup changes, btw?), but I don't have to deal with any caching, rate limiting, or anything else this way.

(Of course, I don't even think you can do anything like that on the web (even JavaScript, cross-domain issues), so your approach is probably required there.)

You could probably get away with remotely updating some sort of declarative grammar/schema, as long as it doesn't allow arbitrary code execution.

If it isn't too slow, you could do the parsing with some remotely-updatable JavaScript, using UIWebView's stringByEvaluatingJavaScriptFromString:.

It hasn't changed since I made http://ihackernews.com