Hey Sekk,
What tax bracket are you in, no need to share profession or salary or anything, but it is kind of needed for looking at the whole picture here? Of course if you don't share it, we can still break things down.
It sounds like I am a lot like you. I am in my mid 20s and thinking someday I might buy a house. There are many opinions on here, but I will write about how I approach the situation, so feel free to disagree with me.
I am in the 25% bracket, so I max out my Roth IRA (maybe not so wise due to my 25% bracket) and max out my 401K each year. Then I throw the rest into low turnover passive stuff in a taxable account and some i-bonds (where I currently have about a 10% down payment for the average house in my area stored).
I used to be in a serious rush to buy a house. But, I am not now. The area live in is probably a great place to buy. Heck MMM lives in the same town and has said so himself. I am a handy guy and can handle almost all of the repairs myself. But, I am in no rush...
The bulk of this comes from not being sure if I will stay in one place for 5+ years. I don't think this is likely, but talk to me in 5 years. It very well could happen.
So, let's say you are willing to stay for 5 years after you have the down payment saved up. Are you sure the Fed will raise rates in 2015? They could go up earlier or much later. The rates in Japan have been near zero for years. So, we don't really know there and I wouldn't be super sure about what they say.
If I were you, I would keep your 401k the way it is today (6%) and max out a Roth IRA (you can take the contributions out at any time and hence use them towards a house down payment). Then save whatever is left towards your down payment in some other account that you can access at any time. If you really feel you want a house that bad then saving up that down payment like crazy is the way to go. In no time I bet you will have that down payment sitting in the bank and then you can max out your 401k contributions.
Is this the optimal scenario for maximizing lifetime earnings on your money? Probably not, but life is about being happy, not dying with the biggest bank account. So if owning a house soon is truly a goal of yours, then go for it and save a ton and don't worry so much about 401k contributions for now.
Always keep in mind that if rates do indeed go up, you can always take everything into your own hands and put every dollar you have towards paying down that mortgage with a 27% interest rate:) It is not ideal, but a big part of the mustachian philosophy is learning to detach yourself from externalizes like interest rates and live in whatever world is thrown at you.
And if that is still not good enough and you miss the low interest rate train, I will probably be kicking myself personally for not getting a mortgage at low rates so you can find solace that their are other fools like me out there. If you end up in the same town then we can go get a beer together.
I hope that helps.