In my opinion, attack helicopters are lousy fighting vehicles. They won't have a
bright future.
They are slow, much slower than a bomber such as A-10, they can hardly
overturn a Stinger or SA-6
they are noisy and not stealthy at all, make them easy to detect
they fly low, make them easy to attack
they are extremely vulnerable, can be brought down by small arms, mortars, and SAM
Attack helicopters are much harder to handle than regular attack bombers
Attack helos carry much less armos than a regular bomber, like A-10, and they
require two crews instead of one in A-10. They also have a much less combat range.
Attack helos can be very expensive, an Apache can cost twice than a A-10. One Apache probably can buy 5 Su-24.
Overall I think attack helos will only be valuable if used in places where the terriain
will give helo lots of opportunity to hide and then jump up to attack. They can be
very effective in some gorrison wars fighting those poor armed militias, insurgents and terrorists, but against a regular army equipped with lots of low attitude SAMs, they will be shot down like sparrows.
Transport helicopters, on the other hand, will still have a role.