Not really high on my list ... more code is needed, and I don't want to mess with any java features (not working everywhere) or temporary storage (risk for big mess, and lots of code and extra functions needed, to clean up after people only uploaded files, but never posted the message) ... this is the 'simplest'/lightest way to allow more than one file ... and that's exactly why I haven't borthered with adding lots of code to the uploads
(and you have the issue of php variables that can mess up even more ... what should the limit be set to? as if you upload 4 files at once, the post data becomes the total size of all files, and if the max allowed filesize needs to be a 4th of that, why cannot you upload one file with 3 times the size of the small ones? ... to solve that one would need to upload each file to a temporary storage, one by one, and use javascript/dhtml stuff to update the post or similar ... and to me that's just way too bloated ... I know vBulletin etc. solve it that way ... but not PunBB:ish over that IMHO )
(also, what happens with a limit of 100 attachments, or unlimited? shoud it have a limit on 4-5 then, but then people want to have 10, and so on ... and then one need to add it to be per forum basis... and then people want to have it per usergroup basis ... and so on ...)
So, I doubt I'll include it in later versions ... I feel it's too much bloat over it ... I added this mostly so people won't need to post 20 posts for 20 files, like it was in the first mod ... now there is a possibility to attach more files, for those that needs it ... and it doesn't mess upp the code too much...
(I think it has been discussed in this thread somewhere ... but it's 6 pages, so worth repeating )