Mathew McConaughey: Dating Dad-To-Be

Matthew McConaughey announced today on his blog (warning: its a loud website) that his girlfriend of one year, Brazillian model Camilla Alves, is three months pregnant. Yet in this month's Playboy magazine, McConaughey is quoted as saying:

"I believe in the institution (of marriage), but I don't feel you have to marry. A kid just needs a mom and a dad."

...which makes a bit of sense considering that also on his website one of the tidbits listed in the "facts" section is that McConaughey's parents were divorced twice but married three times.

There seems to be a slew of celebrity dating couples that are either expecting or have had a child together recently. Just off the top of my mind: Brad and Angelina, Jessica Alba and Cash Warren, Nicole Ritchie and Joel Madden, and Jamie Lynn Spears (Britney's younger sister).

What do you think about so many celebrities dating their pregnant partners, but not getting married (or getting engaged after the pregnancy has been announced)? Do you think it's a trend (good or bad) that celebrities aren't taking their relationship to the next level, or is it merely a sign of the changing times?