Can you text people with other brands of phones from apple's iPhone?

I'm getting an iPhone 4S in a day or two and there's one major concern I have. I've been to the "iMessage" section of the iPhone from the apple website and I saw this:
"If you're a texter, you'll love Messages on iPhone. Now it comes with iMessage, a new service that's even better then texting. Because it's between you and anyone using an iPhone, iPad, or ipod touch with iOS 5."
Does this mean I can't text my family members who have samsung galaxy smart phones? Someone please answer.

No you can text everyone with a phone and texting ability. It's not limited to apple brand electronics I have a iPhone and it works 4 everyone!

That's just a system-installed application that's faster to message people with iPhones, iPods, or iPad. You will be able to text your family members, don't worry.

Apple's IMessage application is joined with regular messages. If the person you are texting is using another iPhone, an iPad or an iPod touch, then your messages will be blue. Then it'll be free to text. The only condition is that both devices must be connected to a wireless network.
If your messages are green, you are using your actuall texting, and then fees apply.
Also if you text another iPhone and you aren't on a wireless network, then the messages will be green.

Ps. A 3G network doesn't count as a wireless network.

Hope I helped!