Bad Habit?

For the last few weeks, if not the last month, Jayson has been doing really well with sleeping through the night and by sleeping through the night I mean from 7:30/8pm to about 4:30/5am.  Believe me, this is a huge improvement from the earlier months of every two hour wakings and feedings.  However this week Jayson has begun waking up again around 2am and then again at 4am.  In the past I used to nurse him back to sleep and put him back in his crib but I'm not offering an overnight feeding any longer (we're not going backwards here folks!)  I've tried changing his diaper, reading to him and rocking him back to sleep which sometimes can take upwards of 35-40 minutes.  This mama has a FT job outside of the house and gets up at 5:30am as it is.  So... I've started to take the easy way out by taking him back to bed with me which lets both of us get right back to sleep.  I know, I know.  We'd finally broken away from the habit of nursing overnight but I fear we're now creating a new habit.  Don't get me wrong, I love the extra snuggle time with my little man but we had been so good from the get go about making sure Jayson slept in his own crib.  Even his first night home he was in his crib, albeit I was on the floor next to it and a nervous nelly all night, but we wanted to set a precedent.  So what else am I to do?  I'm exhausted.  I read online that his recent regression to overnight wakings could be caused by his new found passion to walk.  

Anyone else going through a similar scenario?