What you said about dangerous people not getting custodial sentences is right. She's only dangerous in a car. If there was some way of ensuring she never drove again I'd be happy enough with that.
I agree with that. Well, almost; she disputed that she'd been texting, which probably contributed towards her sentence, but it still shouldn't be four years. That's longer than some truly dangerous people get; if she were banned from driving for longer (twenty years? thirty? forever? she has shown that she is dangerous behind the wheel, after all, and driving is a privilege, not a right) then the risk of her hurting anyone would be pretty much removed.
So perhaps she should have a short prison sentence for lying about texting, which prolonged the trial (and the trauma of the bereaved), but I don't see how four years in jail will help anyone. Yes, it might be two years on parole, but parole is not guaranteed.
The judge's comments also make it very clear that she was given this long a sentence as a deterrent to other drivers; I find that despicable - she should be tried for her offence alone, not for any future offences committed by other people.
I'd like to think her sentence could be reduced at appeal.
One interesting thing about this thread is that nearly everyone agrees that the blame for this incident should be shared between the cyclist and the driver. Everyone's posting that in the usual argumentative fashion (me included), but it seems that nearly all of us are at a consensus on that, which is nice.