I do reckon that by this time next year, when I'll have hopefully gotten the hang of the whole "baby" thing, I'll be so desperate to be doing more intellectually stimulating stuff (I'll be missing my physics) that I'll be making the time to do a little Debian work and a little research (most of my research is theory and can be done with only a computer - makes it easier than if I needed access to a lab), in between nappies and feeding and baby games and so forth.
Maybe I'm not typical, but looking around my female friends I think I probably am. Whilst pregnant with my first I felt the same way you do, I fully intended to get back into things, probably part time, but it was definitely my intention to do that. I took a part time job as a research assistant when he was about 6 months old and found very rapidly that you don't accomplish 50% of the work in 50% of the time, which is quite a disatisfactory situation. I ended up handing in my notice and deciding to try for another baby, but it wasn't really the next baby that changed things, more oh, I've decided this isn't working, we might as well do that now rather than wait.
After that baby I got back into things in a small way by small group teaching, which I did enjoy, but I wonder how much of it was the people contact, rather than the intellectual stimulation. I fully intended at some point (iirc whilst pregnant with the 2nd) to keep things going by working on open source things, but somehow that didn't happen and that was 4 years ago! I haven't even been teaching in the last 2 years as we ended up moving from the UK to the US for my husband's job and I'm on a dependents visa.
Initially I thought I'd try and get a visa in my own right and there were several local possibilities, but I realise motherhood has changed me more than I thought possible, I'm not sure whether it's the hormones or what, but I think my brain definitely slowed down for a while, I finally started to get itchy feet in the last 6 months or so, but before I had chance to do anything about it I got pregnant again, this time unintentionally, I'm fully expecting that it will now be another 4+ years until I stick my head up water again, in the past I cared about that, now I don't, I see it as a chance to branch out and explore other options.
The impression I get from other mums is that diving right back in and really wanting to do that is rare, some do it out of necessity and are glad later, others do it because they think they want to and realise they don't and hand in their notice. I've seen many many people say similar things to what you are saying, most are not still saying it in a years time! One thing you'll probably find is that even if you find you want intellectual stimulation, that the amount of time you have to dedicate to it means that indulging it is a frustration, kind of like spending all day making a chocolate cake and not getting to eat it, you never seem to be able to dive right in and get to the stimulating bit, you might find you have some time then look at the programming task and realise there is a grind ahead before you might get to actually use your brain and suddenly putting on a load of washing seems quite appealing! Of course you may not be like that before, but as I said having heard so many people say similar things, I'm not sure we're all that good at figuring out what we'll be like after having a child, 6 years ago, I'd never have guessed what I'd be doing now, what other interests I've developed etc.
Cheers Anne