Via Responsible Nanotechnology, here is an interesting illustration of the pace of progress:

The first image is from the game Pacman, released in 1980. At the time it was considered to be an innovative video game.

The second image is Half-Life 2, released just a few months ago. It too is considered to be an innovative video game.

These two games are separated by only 25 years, yet they look like they are from completely different planets. One is a flat, pixelated, handful-of-colors-on-a-mostly-black-screen game. The other is a photo-realistic real-time romp through an artifical world of incredible depth and detail. The two games cannot be compared. It would be like comparing a backhoe to a spoon.

An awareness of this rate of change - which could just as well be illustrated by examples pulled from the world of medicine - is why advocates for healthy life extension are pushing for funding now. Transformative technological change in two decades, while perfectly possible, can only be achieved in an environment of public support, expressed desire and high levels of funding. Substantial progress towards working anti-aging medicine is quite possible in a time frame of 25 years - just as substantial progress in cancer therapies has been made in the past 30 years - but only if we start from a position of widespread enthusiasm and a large funding base.

Unfortunately, we don't have either of these items yet, but we're working on it - join in and make a difference!