Anyone reading my posts will know that I have been all for raising the 1Mb limit at the right time, and in the right way. However, after today's events, that time is further away than previously imagined. A lot of reflection and thoughtful planning needs to go into any future change of this nature. More than we might have guessed 24 hours ago.
The first lesson of today is how to get people to accept the necessity of an upgrade path. Then how to get people to use it in a reasonable timeframe. Bitcoin can't reach its full potential being backwards compatible with every ancient version previously released. This is a real challenge.
I too am all in favor of lifting the limit, but these events have nothing to do with it. This event was unplanned.
If you plan it it's really not such a challenge. Starting now and with every future update, simply implement code that says "starting precisely at this date [six months from now] the limit will be raised". If you're running a full node that's older than six months and haven't heard the news for six months, well... You'll just be part of the tiny minority who's out of the loop. Someone may be holding on to obsolete coins and not know they're busted, but that's just what happens if you're out of the loop for so long.
The challenge is not getting everyone on board at once, it's getting everyone's consensus.