I just read an excellent article by Steve Blank about the dangers of Rewriting the Code.

I will add that being involved in a large code rewrite is also an excellent way to commit job suicide. I was phased out of my last job primarily because I bet the farm (at least my part of the farm) on a very complex architectural standardization effort. I enthusiastically followed what the team leader and a very prominent developer on the team wanted us all to do, which was as intricate and modern as perl5 can get. I chomped the bit and then got way in over my head while most everyone else continued working on incremental improvements to running systems.

As with working on any large project that does not have immediate business value, many aspects of a rewrite can attach a huge target around your neck. The political situation became as complex as the rewrite and I believe that putting all of my time into the rewrite (without hedging) -- and then defending my decision to do so -- ruined my position there.

In most organizations, a high-risk project like a rewrite might not be worth participating in unless you can get significant and provable buy-in from other developers on the team, not to mention political coverage from managers across the company. And if the support wanes, I would advise any developer stuck knee-deep in a rewrite to get working on something that is practical and much-appreciated.

Otherwise, the whole exercise can lose you your valuable time and energy, your mental well-being, your job, and even the friends that you made on the job.

Beware.