Oh dear, the "tank is obselete" shtick again...
Lets see, we agree that heavily armoured vehicles are necessary, even for those "light" wars which are supposedly the only ones we will have to fight. The current MRAP's weigh a minimum of 10-12 tons (eg the US M-ATV), with the bigger ones like the the Ridgeback and the Mastiff at 24-30 tonnes, which is about the same as a Warrior IFV. However, off road these vehicles have very limited mobility, which is why the Army uses tracked Vikings for the Helmand "green zone". Now we have to improve their mobility, the logical solution is to mount them on tracks. The Canadian army (after retiring all their tanks after the Cold War) has just bought 100 Leopard 2's from Germany after their wheeled LAV's failed to cope with much of the terrain in Afghanistan. Once you have a heavily armoured vehicle, on tracks, and doubtless mounted with some sort of stabilised weapon, you have a "tank"; something that was supposedly obselete! As for the supposed replacements for "tanks", apart from the vastly increased cost, fuel and maintenance requirements of helicopters, they are about as much use as a telephone directory in the Amazon when they are on the ground. A vehicle can be an excellent fighting platform even when stationary.
As to the merits or otherwise of the CV90, I would aver it's too big and heavy, although a good replacement for the Warrior, and something in the CVR(T) weight class would make more sense, with an up-armoured German Wiesel being a good example. As for the disaster that is the Jackal, the designers have come up with a non-mine protected deathtrap that weighs as much as a CVR(T), but without the 360 degree armour and a 30 mm cannon.