The trackpad on my first 9700 was tilted up and to the left and wobbled around like crazy. My current 9700, the trackpad is tilted very slightly at the top, but it doesn't wobble around at all.
Yup, very common issue. You are more likely to find a 9700 with a wobbly/tilted trackpad than one that sits perfect and doesn't wobble.
You could try exchanging it if it is new. I had to exchange my device due to a faulty "e" button. at&t send me three different refurbs...Two had bad trackpads and the third had a bad mute button. They then allowed me to exchange for a new one in store.
majority of them lean to the top left. it's a design flaw. its possible to fix it but you would have to open the phone up and put some tape underneath the button to prop it up straight.
My wife had a bad "o" key on hers but mine is perfect....Took hers back after 3 days and they exchanged it for another new one without a problem...I find the 2 buttons to the left of the track pad (backup and power/end call) to be a bit tight, almost like they dont even click when pressed, but they do seem to be sensitive enough that they work normally and do not stick..so I guess that is ok. I noticed when I removed the protective film from the screen that the right lower corner of the film was actually stuck in behind these 2 keys so I was very careful to remove it and not leave any plastic stuck in it. I figure there may be some residue in behind and it will probably get more normal with regular use.