What is the meaning of the phrase ‘in timely fashion’?

It was very disturbing to learn that Google will not open source Android 3.0 in timely fashion.

What is the meaning of in timely fashion?

The phrase in timely fashion means quickly, promptly, within a reasonable time frame. One might also hear in a timely manner, which has the same meaning.

For further reference, here are the relevant definitions of timely and fashion according to NOAD:

timely done or occurring at a favorable or useful time; opportune

fashion a manner of doing something

Basically, it means "quickly enough" or "on time".

timely: 1. coming early or at the right time; 2: appropriate or adapted to the times or the occasion

fashion: 2b. mode of action or operation

Note that I usually hear/see this phrase with an article:

You need to pay your bills in a timely fashion if you want your credit score to improve.

Omitting the article makes it sound a little awkward, but not necessarily incorrect.

It means “as quickly as is reasonable in a particular situation”.