Hi and welcome to the board. You did not give us a lot of information to go on. How much free cash flow, if any do you have? Will you get that pension when/if you retire at 45? Will it start at 45 or some later date? How much of your current savings are in taxable vs tax-deferred accounts? Will you both keep working when you have your second child (should you?)? What kind of cars are you driving and do you have car payments?
Having asked all that, you appear to be off to a good start. Maxing your retirement accounts and the 20 year mortgage are good moves. Generally speaking, here's my advice:
1. Live below your means. Especially with vehicles, this seems to be the biggest waste of money for most people. Don't worry about what the Jones' are driving. I drove a Toyota Camry for 13 years, which was always a big joke with my clients, who drove much nicer vehicles. (I had a small CPA practice for 12 years, retired now @ 38). Bottom line, pay off the vehicles and avoid car payments. Read some of the LBYM boards for more ideas.
2. Use a credit card with a cash rebate, or other perks for all possible expenses, always pay them off monthly. some good cards are the American Express cash rebate card and the Citibank Dividend rebate card (for gas and groceries).
3. I assume you have daycare costs. Take advantage of Section 125 flex spending accounts, if available for these expenses, as well as out of pocket medical costs. This can be a huge savings.
4. Consider adding enough principle to your monthly mortgage to pay your house off in 15 years (or your desired retirement date. This is a bit of a toss-up depending on your interest rate and expected return for your investments, but having a paid for house at retirement is a big plus.
5. You will probably want to cash out of the house at retirement and move to a cheaper area. Also, should your house appreciate to the point where you have a gain of $500,000, sell it and take the capital gain exclusion, which is the maximum allowed (assuming current tax law is unchanged). Do this, even if you buy the house across the street and start the meter running again.
6. At least consider purchasing rental property. This topic sometimes gets me in trouble on this board, but if it wasn't for rental real estate, I would still be working today. If you take this route, be sure to educate yourself fully. Rental real estate can provide tremendous leverage for your money and rates are low. Find a property, that will at least break even on cash flow, with a management company looking after it and allowing for 1 month vacancy each year. If you put 20% down, you will have 5 times leverage on your money, ie, if the house appreciates at 4% per year, you real return would be 4% x 5=20% real return on your investment (ROI). We purchased vacation rental property, which served the dual purpose of allowing us to use the property while still reaping the benefits of the rental (if you can't tell, we love the beach 8)).
7. This one should have been first, but I'm too lazy to renumber them

. Be sure you have an emergency fund of 3 months living expenses in a liquid account. Consider a longer-term CD. You would have an interest penalty if you withdraw the money early, but since you only plan to use it in an emergency, it's worth the risk. Also, have enough available credit for another 6 to 9 months living expenses, the more you have the better.
8. Use FireCalc as you go along to see how you are doing. Also be sure to have a written plan for your retirement at 45 and also set shorter term goals for where you want to be in 3 to 5 years. This is a great morale booster and will help to keep you on track.
9. Ask specific questions on this board as you have them. You will get some great responses and some different perspectives.
10. Read lots of books on the subject. You can find a great list of recommended books on the retireearlyhomepage.com website.
Good luck to you!
The Beachbumz