There's no incentive to save for college anymore.
The financial aid process absolutely punishes anyone who has any actual assets to pay for college. The system is basically an asset tax under the guise of "here's what you can afford to pay". If you have assets, you get reamed at 20-25% / year. (It's only 5%/year for 529 plan assets, but that's still a tax.) If you have no assets, you can get aid (aka a price reduction), and if you can't get aid you can still borrow the money at low rates.
401K and IRA savings are immune to financial persecution. Home equity is safe under the FAFSA system (mainly public schools) but not the Profile (more elite) schools. So it makes more sense to stash income in a 401K, bargain for a lower sticker price, and then hope that the 401K money earns more than the interest on the student loans.
If you've got bright kids or are aiming for a private school, you're better off not paying off your mortgage early, because home equity gets taxed at like 20%/year as well.
If you've got income, that's effectively taxed too, at 25%, so if you're in a high-tax state you can go from the 25% or 30% federal bracket, through a 9% state income tax and 9% sales tax, and toss in another 25% in "college tuition cost increase" tax, and watch yourself paying what is effectively a 75% marginal tax rate. It's even worse than living in Europe...
You could rephrase the way colleges are priced as "from each according to his ability, to each according to his need", and watch Marx and Lenin smile, except that their spirits have seen how that system fails, and this one is failing as well.
The plan for paying for college (especially for second-income parents):
1) Save for college tuition only by way of a 401K or IRA
2) Minimize home equity (store up savings in the 401K/IRA instead of as home equity)
3) Quit working about 2 years before your oldest goes to college, to show little income on the student aid forms.
4) Reap effective income of $15-60K/year per child in the form of scholarships and tuition reductions for each child.
5) Live off 401K or IRA while students are in college. The 10% penalty tax might be the only tax you pay!
6) Resume working and saving for retirement after the kids finish college and the financial aid office no longer has a death grip on your ability to accumulate wealth.