Just as a minor point, re loading a fair whack of information into the Help function on board new Macs covering 10.7:
Even if 50,000 Knowledge Base articles were included at an average size of 20KB, that would only amount to 1GB (only 0.2% of my hard drive). Hardly noticeable, but very convenient.
Don't compare it to the size of your hard drive. Pre-Lion, when the OS was still being delivered on DVDs, compare it to the size of the DVD. Remember that Apple has to squeeze a lot of information onto that DVD.
As of Lion, the OS is delivered as a download. Adding a "mere" 1GB to an already 4+ GB download would have people up in arms, and rightly so. Heck, even the developer tools are split off into a separate download, so that only developers need to download them.
Especially note that, as the only way to get anything
is to download it, it makes sense to download stuff on demand. Don't waste bandwidth downloading everything and the kitchen sink; just download what the end user expresses an interest in.
And don't forget that pre-fetched data is often stale data. Those 50,000 Knowledge Base articles you mention are constantly being updated. Is it really worthwhile to repeatedly download them each time they change? We have this thing called the World Wide Web that deals quite handily with voluminous but constantly changing data, by re-fetching each page as it's asked for, rather than attempting to pre-fetch the entire web in a pointless attempt to never have to fetch anything.
Think of the Knowledge Base as just another website. It has lots of information, more than anyone has time to read in its entirety, and is constantly being updated. You wouldn't dream of keeping the entire New York Times website always up-to-date on your computer; why expect that doing so with the Knowledge Base would make any more sense?