Hi @vmassol,
I compiled a list of random thoughts that came to my head. Some points may not be directly ideas and some of the points may be better in the usability pain points thread, which I, by the way, think you should “pin”.
A lot of these points are highly subjective.
I still hope that you find them useful.
Visibility: It is unfortunate that it’s pretty hard to get visibility on the big search engine(s) as every search phrase containing the word ‘wiki’ seems to contain mostly results pointing to wikipedia. I myself found it really hard to discover xwiki although I searched a lot for wiki and mediawiki related stuff in the last few years. And I kept searching for alternatives to mediawiki and evaluated and discarded a few before I found xwiki (finally 
)
Maybe a first step would be to review “all” the wiki comparisons and correct and complete them, if necessary (e.g. wikipedia or wikimatrix to name only two high ranked in my search results.)
Documentation I: There is a lot of documentation, which is good, yet it “feels” scattered. There are only few walkthroughs. To install xwiki with tomcat and mysql you need to read at least two or three documents just to get started. While I know this is considered the hardest way, it is currently the only way that I see to run xwiki in the companies I know.
Altough I really wanted to try out xwiki I did not feel really encouraged, because the installation documentation looked like a real hard piece of work. I guess if I had to evaluate xwiki it may have been out of the game at this point. This may be only me, but I became extremely maintenance and operations focused, so I try to avoid everything that “smells” like trouble and hard to read installation documents are the first sign of trouble for me.
Also the documentation is often sprinkled with hints for or references to old or “obsolete” versions. While they may serve a purpose for some, I found them distracting.
Documentation II: There are a lot of “weird” search results in the google search index. Especially when I searched for more advanced stuff I found myself a lot on PDF Export or history pages for articles. Maybe you can prevent google to index these?
Don’t fight Sharepoint, complement it: I digged up this Xwiki vs. Sharepoint comparison and while it is dated and has a lot of valid points I found that attacking Sharepoint is mostly fighting a losing battle. So it may be better to concentrate on the points where you can add value for a company alongside Sharepoint not trying to replace it. Maybe have an extension (if there is not any yet) that adds integration to sharepoint (export to sharepoint,…).
Get more enterprise “aware”:
Just one example: Asking for “grant all privileges on *.* to xwiki@localhost[…]” (see here) is nothing I could pull off easily in most companies I know.
Create tutorials:
Showcase the awesome features that xwiki has. Get users into xwiki fast so they feel it is fun and natural to use it. Suggest admins a good way to set-up and maintain xwiki. Show developers how to create small apps, establish xwiki as an extensible platform that helps them. Encourage contribution.
Focus on content editing:
Editing content is the bread and butter functionality of xwiki for me, so it should it be as easy as possible. So bugs in and enhancements for the editor should have a high priority (and no, I’m not at all, hinting towards, e.g. Loading... )
Documentation III: If you try to dive deeper, I found that the documentation is getting more incomplete and scarce. I found myself often on the source level, which I don’t mind, except that finding the source code is pretty hard, especially as the full API documentation is broken since at least months and the current 10.4 API doc is segmented in modules and spits out HTTP 400s for a lot modules (e.g. here and here and more).
And you may have guessed already: I’d really love if the development documentation would be way more like a walkthrough than it is currently. I’m still struggling to setup my dev-box. But maybe others will enjoy it too, if they felt more “welcomed” and supported as devs.
To sum it up: These are a few points that I’d like to see improved and that I guess may be liked by others too and maybe answers your questions. I hope you find them helpful.
rbr