Getting only a 35mm f/1.8 prime lens will limit your photography to normal perspective. This focal length is good enough for baby whole body shots, but will not be good for closeup portrait. You will also need a wide angle for landscape, travel, and family group photos. A mid range tele will be good for portrait and sports action as your child grows older. Having HD video capability available is handy for family use. I often use the HD video on my Canon 5D Mark II which has excellent quality, and the T1i is probably quite similar. Your budget will not be enough for a fast zoom lens.
Things you will want to have for a nice basic setup and great family photos:
D-SLR with a general purpose kit zoom lens (usually 18-55mm)
A mid range tele lens preferrably with IS (usually falls within the range of 55-300mm)
A fast prime lens like 35mm f/1.8, or 50mm f/1.4, or 50mm f/1.8 for night photos or low light shots where you cannot use flash
An external bouncer flash with diffuser (make sure it can tilt and swivel)
A polarizer filter
A remote trigger
A lens cleaning kit
A bag that is big enough to hold all these gears
An editing software like Photoshop.
An external hard drive to back up all your photos and videos
Your budget should include the above essential accessories and peripherals because these things can improve your shots more than a more expensive camera body.
The HD video capability in the newer D-SLRs is a very handy function, with great quality, but it is not a camcorder. You need to either autofocus before switching to video mode, or do manual focus (it has autofocus but it is very slow in the video mode). This video capability is good enough for family clips and baby clips. Audio is decent as long as you don't use any autofocus function or snap a shot during video clipping. For a lot of family clips, I have used the D-SLR video and left my camcorder at home. But for sports action or birthday party video where kids are running around, you will definitely need the camcorder. I found the Litepanel micro to be a very good external LED light for video use.
If you don't need video, the Canon 50D has faster fps and is better for sports action. But your baby will not have any fast action until a few years from now, so not something that important for you at this time.
I'm planning to step up from a canon point & shoot to my first dslr and I'm leaning towards the Nikon D90, but also looked at the Canon Ti1 and 50D. Most of my photos will probably be family related as I have a 6-month old son, but I'm also interested in some outdoor/landscape photography.
Looking for thoughts on that and also if I go with the D90 I've read mixed reactions to the kit lens. What do you think of this set up: get a D90 body, and the nikon 35mm f/1.8G prime lens which seems to be rated well.
How much, if at all, will I be limited with this combo? I'd rather not be changing lenses all the time, but if that set up doesn't work so well, what would you suggest?
My budget at this point is up to about $1,500 for a body + lens(s).
All thoughts are appreciated, thanks!