1. What does it do? If there are several options on the market, what does it do that it's competitors don't?
2. Will it run on my machine?
3. How do I install this freakin' thing?
Regarding the first question, most distro sites do a pretty good job. Usually, the information about what makes a particular distro unique is on the front page, exactly where it should be.
Question #2 is the big stumbling block for most distros. Specifically, I'm talking about system requirements. This stuff needs to be accessible from some very prominent place, like the front page or the FAQ, not buried in a wiki somewhere. Most "About Our Distro" pages tell how a distro was first developed in 2002 by Joe Schmo in his employer's cubicle/a university lab/his mother's basement, etc. I guess that's good information, but I don't think the average user cares. If I really get comfy with a distro, I might want to know that stuff, but under no circumstances should it be more prominent than the system requirements. The system requirements don't necessarily have to be exact. They can say something like, "OurLinux can run on as little as 64 MB of RAM, but 128 MB RAM is preferred," and so on. When I can find this information at all, it's usually kind of buried.
Also, it wouldn't hurt to remind the user how to find what kind of hardware they have, because I can almost guarantee that the vast majority of users out there don't know. When we first acquired Lazarus, I asked Mr. Williams, "What are the specs on it?" He gave me a blank look and replied, "Uh, 64?" And this was after he'd been using the machine for 6 years. I'm not calling Mr. Williams stupid or anything (he's certainly not), but I think it's a good illustration of how most typical users don't exactly have their specs committed to memory.
Question #3 isn't as problematic. I can put together to burn the .iso to CD, boot from said CD and follow the rest, but it wouldn't hurt to have that spelled out. Also, sometimes there are commands required, although most distros that require these are pretty good about mentioning them up front.
So, if anyone wonders why more people don't try Linux, I really think the issues discussed above are a big part of it. I'm not even going to get into the WiFi support issue, as that is outside the scope of my project. If I ever decide to blog about my Linux experience on my laptop, I'll discuss it there.