What is your asset allocation in your 401K and IRAs? It's correct to have them maxed out, but you still need to pay attention to how they are invested.
20% to 30% Bond index
30% - 40% Large Cap index
~25% Intl index
~20% Small cap index
As things grow, add an REIT index for inflation protection.
Vanguard has all those in mutual fund and ETF formats.
Be aware of taxes. If you think your income bracket will be lower in retirement, then keep dividend producing securities (Bonds) in the 401K and growth securities in your brokerage accounts. If it's all for retirement in your plan, then keep both 401K and brokerage combined in your allocation strategy.
Set up a spreadsheet for your net worth and create three pools of money.
#1 -- Emergency fund -- Decide what you think you need and allocate it conservatively. Cash, ST bond funds, etc.
#2 -- Life goals -- Kid's college, new house, career change etc.
#3 -- Long term goals -- 30 years of retirement more than 20 years away. Invest as aggressively as you feel comfortable. Still keep ~20% bonds for stability and keep it diversified. Don't forget that international and small company funds are a good way to pick up uncorrelated risk and return.
Combine your totals in the spreadsheet and you should be able to figure out what your overall allocation should be based on the timeframe that you need each bucket of money. Just make sure that your emergency fund (#1) is outside your retirement accounts. I think it's generally OK to keep #2 & #3 combined in concept as long as the total outside the retirement accounts can support your goals in #2. You will have to re-allocate the money in your 401k + IRAs as you spend those bigger amounts (house, college, etc) anyway.
tldr: Figure out an allocation strategy that includes your life goals.
http://money.cnn.com/tools/assetallocwizard/assetallocwizard.html