On my radar:
:: Image and YouTube embedding
I know this is feature is much-desired. Mods will be able to embed images and videos. There won't be any special syntax for it; any image (PNG, GIF, JPE?G) or YouTube URL on a blank line (no other text) will automatically embedded
:: Greyscale theme colour alts
Now I'm able to generate the various images via a script, it won't be too hard to create alternative colour themes for Greyscale. These will be selectable from within Greyscale, rather than being separate themes entirely so that users can choose their own preferred colour scheme and the admin can set a default.
:: stick / unstick button
The ability to sticky / unsticky threads within NNF (without having to use FTP) has become a necessity. This is not difficult to add, but will be limited to the site admin only and not mods. The first user listed in mods.txt will be the site admin who will have access to many more admin features in the future.
The long-term goal is to provide a management panel for the site admin where they can do a lot of administrative tasks without having to FTP in.
:: Running without HTAccess
I am aware of the desire for this feature, but it's not the easiest thing to implement elegantly. This will be handled via a long branch, much as DOMTemplating and translation were.
The core difficulty is that all URL construction within the code must generate URLs that work with or without htaccess. At the moment it's all just string concatenation, but I'll have to add a helper function, which will complicate the code a bit.
I'm in two minds about how to best handle no-htaccess. I would like to move the NNF code out of the root and into a sub-folder, but that would break being able to silently fallback to no-htaccess mode without any work on the part of the site admin.
*Areas for Discussion*
Some areas I feel that need community discussion
Without a database, it will be hard to implement effective bans. The only option will be IP-based bans, but care must be taken to produce a simple and elegant system that won't break if left alone.
The most difficult aspect is that IP data is not stored with each post; NNF does not know the IP of any user who made a post. This is tricky problem to overcome without creating some form of messy database that duplicates data. Your input on methods we could use to track IPs and effect bans would be appreciated.
:: Flood control
Hand-in-hand with banning comes flood control. There's no limit at all to how quickly anybody can post. I don't wish to impose a limit, because this breaks the zero-hurdles approach to NNF. I would never want to prevent someone from posting something because of pissing them off with hurdles. Bad people are a problem, good people are not and shouldn't be treated like one. If you've any thoughts on flood control, let me know.
*Any personal requirements?*
Lastly, if you have any personal requirements for features in NNF, please add your reply. I feel it helps to debate an idea here to find an elegant solution that's unique and treats the matter with care and consideration. (rather than a "let's solve it with more BBCode!" kind of attitude)