Frank's proposal

You might want to get more feedback from other Wikipedians. There are a ton of external tools that have emerged to help out with Wikipedia. There are also a bunch of internal processes and tools that aren't particularly good. If I were to focus on the ones that veterans have the stomach to use, but new editors often find too tedious...

• Finding reliable research. People link to key searches in the AFD template, but the searches are grossly inadequate. A lot of debate always ensues as veterans try to explain that a blog is not a reliable source. You'd bridge a huge gap between new users and veterans if you had a dedicated search engine that only surveyed a list of reliable sources. (e.g.: a white list approach, as opposed to a black list)
• Doing a proper citation. Have you seen our citation templates? I imagine that even half of new users are willing to find a website that backs up their claims. It's not that different from posting a link in their facebook or their weblog, and then talking about it. But they probably just say "forget it" when they realize that citing stuff is confusing as hell. So a lot of stuff goes uncited, and it leads to disputes over facts.
• Getting feedback on an article. I'm talking about the complicated process of peer review, especially. But I'm also talking about good article and featured article nominations. New editors probably work on an article, and wait for feedback, but then get nothing. Show them how to get feedback. Nominating articles for deletion or for merger too. Feedback is a key way to bridge the gap, and the most experienced editors constantly solicit feedback all the time. Maybe not just peer review, but at least a third opinion. Maybe even create a specialized "my first peer review" feature for new users, so that the veterans know to avoid using jargon, and cover the basics.
• Merging two articles. Let's focus on that, because it could really help new users avoid controversy. New editors often get into trouble by pushing to delete stuff that could be merged, or creating new stuff that gets deleted when it could have been merged. If suggesting a merge were easier, it would happen more often, and solve a lot of conflicts painlessly.
• Creating a discussion. I suppose liquid threads will make it a bit easier to have a discussion about an article. But there ought to be an easier way to create a centralized discussion that crosses several articles. Veterans do this all the time, but these discussions are tucked away in some complicated place that you're lucky to know where to even look.
• Formatting an article. "What You See is What You Get" is only half the battle. The other half is making sure that "What You Get is What You Need". No sense on letting people create all kinds of wonky headings if there is only one established way of doing your outline.
• Understanding a policy. Even just mousing over an acronym like "WP:V" should pop up a tooltip with the nutshell: "Material challenged or likely to be challenged, and all quotations, must be attributed to a reliable, published source." Key to this, however, is making sure they aren't gamed by veterans who link to mere essays (whether in good faith, or in bad faith trying to fool them into thinking something is policy).

That's just off the top of my head. I might be missing a really important one though. But all of these things will either help new editors function like veterans, help new editors learn what the community expects, or both.