Just wanted to pop by Lala and say I don't think it's an unhealthy thing to be thinking about how you will have a girl next time - I'm pg with DS2 at the moment too and do spend time looking into my options (either swaying or more extreme measures) so that I figure once I have some sort of 'action plan' together, everything about this pregnancy will become more enjoyable. I often find myself thinking "Hurry up July, so I can bake another!" although DH and I have decided to wait a few years before going for our third and final.
For me, researching more has given me a sense of control over things, and a sense of what to aim for in the future. If you wait another 6 years for example, who knows what will be available to us all then? There may be new high-tech options even.
Sounds material but have you started shopping yet? I'm finding gathering bits together than are slightly different (we're going for greens instead of blues this time!) is helping on a more frivolous level (excuse spelling!)