I've been working full time for a month now. DD is 5.5 months old. Initially the decision to go back to work was daunting because I quit my job so I was looking for work and also I felt guilty. But the reality of returning for me was better than I expected. I returned for a few reasons:
1. Financial
2. DH wasn't coping being at work and I wasn't coping being a SAHM
3. I enjoy working
4. I think I was on the verge of PND so I needed to get out of the house and away from being mum for a few hours for my sanity

Once we found daycare we were happy with I felt heaps more comfortable about returning. I was also lucky enough to get a job close to home in a family friendly environment with flexible hours and great benifits.