Comment 9 for bug 608631

Yes, fundamentally we may replace all [nbsp] by nnbsp.

But currently nnbsp is not widely used or even known, it's not even on our translation guidelines (eg gnome-l10n-fr, lp-l10n-fr, ubuntu-l10n-fr...; even if these last 2 will surely change when this bug will be fixed).

As said in the first post and by verdy_p, even if nnbsp support seems to be ok now, there might be some bugs with some fonts or rendering engines.
And as nnbsp support is quite new in modern browsers, we may need to fallback on [nbsp] for webapps (to support IE 6/7 or such horrible things).

So I think that [nbsp] is still needed for compatibility purpose.

About a "graphical" display, this is a good idea.
But, unlike spaces or newlines, all keyboard layout do not have a mapping for nnbsp.
So it may still be necessary to input nnbsp via [nbthin] in some cases.

And, even if the "char eating" bug was fixed in Firefox, I'm not sure it was in other browser (I also tested with the last chromium build and it works).