My Jeep gets the same way. When it's below 30* or so, it starts to crank a little slower, and a little longer, and the startup is a bit rougher. By the time it hits single digits, it's about 5 seconds of cranking, then it spits a bit and catches, and runs rough for a couple minutes.
In my case, the hard starting due to the poor spray pattern from the stock injectors. Somewhat slower cranking in the cold is normal. If the battery and connections are ok, and the ignition system is in good shape (spark plugs not too old, etc), then it may be normal for the car. Did it do this last winter?