Although I like the basics of this RFC, there is some stuff here that should be in a plugin rather than in the core, IMHO. My idea about phpBB (and one of the major reasons I prefer it to IPB) is it's light base. Let's look at these:
Unknown Bliss wrote:WYSIWYG Editor as well as Rich Text Editor and Preview
I think the basic editor should always be included and available for the user. Think of mobile users for example. Mobile browsing will become more used in the future (in the Netherlands there was an ~30% increase in mobile use last year for example, and predictions by telephone networks are even more positive for the next years). A WYSIWYG or RTE is way to bulky for that.
Also, one should keep in mind the possibility for server sided BBcode parsing (think of TeX or such stuff). There has to be a good solution for this when using an WYSIWYG editor. Not that it's impossible, but I think it will become very bulky an heavy on the client side.
Unknown Bliss wrote:Quick Reply - Extended to include BBcodes depending on Users Chosen Prefrence in UCP
You mean that a user can define which BBcodes he wants to be shown in the QR? I think that's way too complicated. The basics (bold, italics, underline, url, img) should always been shown, and the
admin can choose what other buttons to show directly. All other buttons should still be available through some kind of collapsed menu.
Unknown Bliss wrote:Topic Tags - For SEO have tags/keywords for the topic.
While I doubt the SEO gain for this, I think it's useful for the users and to keep users on the website. There should be a limit to the number of tags a user can choose though.
Unknown Bliss wrote:Related Topic - Have any similar topics listed below the topic content.
[*]Detecting Duplicate Threads. When multiple topics of the same title in the same forum display a warning first.
Instant, while typing you mean? While some people may find it useful, I think this should be a plugin. Many boards don't really care about this or may even dislike it. Think of boards like phpBB.com for example, or any other board dedicated to a certain subject. There will be many similar topic titles and perhaps even with similar content of the first post in that topic (think of the support request template). This will probably result in many false positives, making it annoying rather than useful.
Unknown Bliss wrote:Hidden Topics - Be able to hide topics to permission level (moderators and administrators) rather than moving or deleting the topic.
That's a useful feature, that
already will be included in 3.1. People should still have the possibility to use a trash can and/or permanently delete topics and posts.
Unknown Bliss wrote:Message Multi-Quote - Have a slightly better multi-quote than the quoting system in Topic Review which is very 'hidden'
True.

Unknown Bliss wrote:Topic Rating
This should be a plugin, IMHO. Some boards find it useful, but for many boards it's just a lame feature. IPB already had this in their 2.x branch, but of the boards I've seen most of them don't use it. Since this is easily added through a plugin, I think it shouldn't be part of the core.
Unknown Bliss wrote:Reply Notification System - Have the reply in the email so a user doesn't have to log in to see the message
[*]Posting by email - Being able to reply to a topic by sending an email
While this does have some advantages, I think there's a risk for the board admin here since there isn't the need to visit the board anymore. I don't want this my board, no way. Plus, since mobile browsing is becoming more and more in use, I think the need for this feature from a user-perspective isn't really there either.
Unknown Bliss wrote:Advanced Image Attachment - Having a image attachment system like the Titania screen shot system.
What's the benifit of this for a general board?
Above message may contain errors in grammar, spelling or wrongly chosen words. This is because English isn't my mother tongue. My apologies in advance.