Right now, we have ABSOLUTELY no data to suggest that life exists outside our solar system. Still, astronomers are putting together a persuasive line of evidence that planets may be common around other stars, and in our particular solar system, there are several spots where life could have gotten a fleeting foothold, and may even exist today: Mars, Europa, Titan. So, I think it is very plausible that at least bacteria exist on planets orbiting other stars. Higher forms of life...well...that's a very hard nut to crack even if we do detect free oxygen in the atmospheres of distant planets!