[ramchip]

The problem isn't on the client, it's on the server. Using the Chrome plugin would break their apps just as well as using Chrome itself.

To test all the web applications currently used by HMG departments can take months at significant potential cost to the taxpayer.

[skymt]

Chrome Frame is only activated on pages that specifically request it with a meta tag or HTTP header. If they deploy Chrome Frame government-wide, they could start developing modern web apps without losing compatibility with their legacy IE apps, allowing a gradual transition.