This is having read the articles in The Times which broke this, its under a paywall so have just some comments on it
(I will read grumpyblue's post and the Guardian article about Chelsea saying its just a strategic review, although I suspect that may well be a standard club response to it getting into the public domain, as much as I hope it's exactly true, as this could or would be truly devastating for Chelsea)
The Times has splashed all over various sections of their paper a potentially big story
Abramovic is wanting to sell Chelsea for around £2 billion
Speculation that having to miss the FA Cup final which Chelsea won, through the withholding his travel visa, has caused him to seriously and sharply scale down any future investment in the club and the surrounding area.
He cancelled plans to redevelop Stamford Bridge, saying that's now not happening and has perhaps now thought about whether he wants to remain at Chelsea at all.
There is the whole Anglo Russian angle with relations being as bad as they've ever been too.
For £2 billion, or even if less than that, there aren't going to be too many investors who could take it over, and those who could would probably be in it for financial reasons alone.
Therefore is Chelsea, a club who keep winning trophies almost every season, and now seem almost fixed right at the top end of the English game, be an attractive investment for say oil states or Chinese billionaires, maybe even Usmanov, is there sufficient potential for financial rewards?
They've had around ten managers in about the last fifteen years but have broken all the perceived correct rules for a well run club by bringing in trophies by the bucket load, including the very top ones, prem league titles and champions league winners.