Looking for Answers about Vizio VIZIO 55" Class LCD 1080p 120Hz HDTV , E550VL?

According to the user manual, yes it is. Just be sure to get the mount for the large 55" size and follow mounting directions supplied with the wall mount.

As a stand alone tv, no it is not able to connect to the internet, but with many new devices coming out, like the logitech revue, you can make any hd tv an internet ready tv and use google tv to download apps like pandora, netflix, youtube, etc. Really is the future of TV and entertainment.

No it is not

No, but you need HD to enjoy it's benefits.

Tv's are measured diagonally. corner to corner.

Any time you take a lower resolution picture (still picture or moving) and stretch it to a larger medium then it was designed for it will look pixelated and the color contrast will not be vivid or sharp. The good thing with a TV like this one is that they try and compensate for this by "line doubling". This helps and I have had friends and relatives that bought HD TVs hooked it to the cable box with standard connection or did not know to go to the HD version of the same channel on their HD cable box. They are happy with the picture (and much larger size).
So yes this will give you a good picture but when compared to an HD channel you will notice the difference big time. If you don't wish to upgrade your cable box then at least buy and HD antenatal to grab those Free local HD channels! This can be done with the cheapest antenatal out there. Although if you are far from the broadcasting antenatal a better quality and/or one that is powered (has a power adapter that plugs into an outlet) is a must. Don't ever blame the antenna for not working as your location and anything like buildings and mountains getting in the way is the problem.
Also keep in mind that some TVs will automatically stretch a non HD channel to fit the wide view of all TV's out there now. This makes everything look wider especially making people look fatter. If it does not (I prefer to see it this way) the non HD channel will be a square picture with black bars on the side of the picture. The picture may seem smaller but at least it's not distorted from it's original shape. Either way, this is a setting you can change and most remotes have a dedicated button for this.
For me it's worth it to have an HD cable box but remember that you have got to the HD version of the channels you watch that are usually in the thousands and sometimes end in the same as the non HD channels (if CBS is on 09 then the HD version might be 1009). Something to get used to but easy if you write them down.
One last thing if you do get an HD box and it's a DVR (records your shows) recording in HD takes a lot more room. Recording some worthwhile shows in HD and the rest in standard resolution (ie recording shows from the lower channels not the HD versions in the thousands) will slow you to record more before your DVR gets full.
I know this is much more info then you probably needed but others can benefit from it.....I hope :)

no this one does not.
just purchased one today. got it home expecting the wireless and the vizio apps. but none...

No, it does not.

Yes,have mine hooked up to laptop w/vga,audio.Can also be hooked up through HDMI.

THEY ALL HAVE SOME GLARE, YOU WON'T NOTICE IT!