I don't think Test cricket is in particular trouble in India, apart from their inability to find a good fast bowler who can be a ten year player. India's Tests away from home get extremely high TV ratings (which is good money for the countries they tour) and they are still playing a reasonably good number of Test series.More interesting is India's attitude to yesterday's game. They were pitiful and looked disinterested in the Test series yet seemed galvanised and motivated by a meaningless one-day match.
It does rather reinforce Matthew Engel's view that apart from in England Test cricket is in serious trouble around the world with declining attendances and general lack of interest. Indian fans in particular seem to regard the IPL as more important than the national Test team these days.
In defence of their team yesterday, it was mostly a different bunch of players in the ODI team swapped in after the Test series and you can't blame them for going out to prove a point - in the case of Rohit Sharma (52 opening) he's been trying to get into the Test team for years. In the case of Dhoni and Ashwin, you can't accuse them of coming alive for the ODI series because they both had good performances in the last Test and they have a good track record in all formats.
You might not remember though, England has come back from a ****house Test performance and come alive for the ODI series a couple of times in the recent past too. In 2006-07, they came back from the humiliation of losing the Ashes in a 5-0 whitewash to win the World Series, and over here last summer they performed relatively well in getting one more victory (1) than the Tests (another 5-0 whitewash) and pushing Australia hard in a couple of very close losses.
Test cricket is just as strong (i.e. firmly established as the most elite format of the game) in Australia and South Africa as it is in England. Australia has strong crowds against most opponents (and the option of having a winter series at smaller northern grounds for weak teams like Bangladesh), and the strong traditions of Brisbane opening the summer and the back-to-back matches of Melbourne (the biggest crowd at any match in the world, every year) and Sydney after Christmas.
New Zealand is reasonably healthy, but not particularly strong either as they struggle to pull crowds to their away matches.
If you're looking for countries where the Test format is genuinely in trouble (and for differing reasons in each) you need to look at Sri Lanka, Pakistan and the West Indies.