It's all change at the top of Yukos, the Russian oil giant that is the target of the Kremlin's latest anti-tycoon campaign. Mikhail Khodorkovsky, the "oligarch" who ran the firm and who was arrested last week, has stepped aside; a new, lower-profile management team has been installed.

So what's next? BBC News Online picks through the evidence.

So, is this the end of the affair?

The beginning of the end, perhaps.

Russia's markets seem cheered by the change of personnel, sending Yukos shares up 13% on Monday.

The fly in the ointment is Mr Khodorkovsky's ownership of the 44% stake in Yukos, which is frozen, but not confiscated.

A diplomatic solution would be for Mr Khodorkovsky to find a buyer, and step away completely from the firm - and maybe therefore from the criminal charges that still hang over him.

A bloodless ending like this would suit the Russian authorities, and judging by his placatory public comments, it might also suit Mr Khodorkovsky.

But things are rarely that simple.

What's next for Yukos?

The company should avoid most of the remaining heat.

Its new boss, Simon Kukes, is wholly inoffensive to the Kremlin, being a grey-suited executive rather than any kind of tycoon.

As far as shareholders are concerned, too, he is an eminently safe pair of hands.

He built regional oil producer TNK into a firm attractive enough to be taken over by BP earlier this year.

How does President Putin come out of this?

With a surprisingly small amount of egg on his face.

There is, of course, a great deal of international hoo-ha about the case, but nothing seriously to touch the Russian president.

In Moscow, a few babushkas were photographed waving placards in protest.

But it is hard to believe that the generality of the Russian population gives a fig for the fate of a billionaire, or for the company that - as many believe - he stole from the state.

With elections approaching, the Yukos affair can only do Mr Putin good.

Can we expect actions against other oligarchs in the future?

Yes - not that there are so many oligarchs left to pick off.

The next obvious target is flamboyant Anglophile Roman Abramovich, who is unfortunately entwined with Mr Khodorkovsky, as well as with others on the Kremlin blacklist.

On the same day that Mr Khodorkovsky stepped down from Yukos, Russian prosecutors said they might probe into the privatisation of Sibneft, the firm whose recent merger with Yukos helped make Mr Abramovich's fortune.

Most of the tycoons still at large in Russia have long ago pledged allegiance to the Kremlin - notably Vladimir Potanin, an oligarch of the old school who has been Mr Putin's most prominent corporate backer.

What lessons should we draw about business in Russia?

That things have not improved as much as most Western investors seemed to think they had.

Over the past few months, the West seemed to have convinced itself that Russia was on a roll again; ominous whiffs of the mid-1990s bubble drifted through the markets.

The Yukos affair is a reminder that, in the new Russia, property rights do not hold the same sacred force as in the West.

This holds true for the authorities, who seem willing to confiscate assets far more blithely than governments in full-fledged market economies.

But it also holds true for the oligarchs themselves, whose empires were built by means of a similar disregard for the shiny capitalist ideal.