Azwraith,
It really depends on what you want in the long term. With mortgage rates as low as they are you can probably buy a lot of house with the equity you have and a reasonable payment. But you do need to keep in mind that a larger home will cost more in other areas, utilities, taxes and maintenance will all be higher.
How long to you plan on staying in the home? the market may take a while to settle down, if you plan on selling in a few years I would probably stay put.
Do you see your housing needs changing in the near future? Do you think you will need more space for a growing family? How long do you expect to be working?
Personally I am not a fan of having any debt, but managing a reasonable amount of debt can be a good financial technique. If you didn't have a mortgage payment would you be putting the money into a savings plan? If so with the current market conditions and the uncertainty of the financial markets a conservative savings plan will PROBABLY out perform a Mortgage for building savings in the short term. The other side of this is that when rates increase that next home will cost you more on a monthly basis, and that could balance out any gains you would have made.
My personal goals are to keep my monthly living expenses as cheap as possible and to only keep about 15 - 20% of my portfolio in non-income producing real estate (ie. my home)But I work on commission and have no income guarantees, your situation is probably different and therefore you need a different plan.