You don't have to fill every bit of open space in your design, but symmetry can be important to the final look. I would object to the window being framed by less wall space on the left than on the right, but that's just me. Would you consider using a smaller cabinet to the left of the window, or adding a stack of stack of open cubbies to the right of it? It would look like the wine cubbies below. Note that in this image, the windows are also not symmetrically framed, in fact, nothing is symmetrical! But the space is unified with bs tile and is framed on all sides.

Do you have measurements?

I like eam's idea of the open cubbies.

I may be missing it, but did you include a tall skinny cab for cookie sheets/pizza pans?

Thanks for all the suggestions! I have to say, I think eam's idea for the cubbies might be most amenable to our overall design. I think I'll try to find something similar or ask the trim carpenter if he can make them. Changing the cabinet sizes isn't an option for us because these were the only ones that we could guarantee IKEA will be able to deliver by our deadline. And Beth, no we don't have a vertical skinny cabinet, but some of the horizontal ones in the island should work for that kind of storage. Thanks again everyone!

Everyone's kitchen has some sort of balance between form/function, and only you can determine what is acceptable. For me, that would have been a no-go.

I'm intrigued by schnoodlemom's off-center curtain suggestion. It would make the window appear wider, and therefore be centered between the two cabinets. However, that would make the sink appear off-center, which would be a whole other issue for me. ;)

Do you know if your Ikea allows you to maintain the discount? At my store, I got the 20% off until the next kitchen sale started, which was a couple of months later. I was able to change my mind on a few things, return/exchange as needed, and still get 20% off. I know others on Ikeafans mentioned that they got it for one return visit, or not at all, but it might be worth checking out.

Gennifer - they will honor the 20% off on the items that weren't in stock, but likely to be back in stock soon when we placed our order but didn't extend the option to anything else. Wish they would, that might give us more options. We're on a tight deadline since our home will be in the local Parade of Homes so there's not a lot of time to make switch-outs.

The house isn't built yet? Just make the window a little wider.