First off, let me say this product works as described, having 16GB worth of storage is great, I put my entire unprotected music library on it (Amazon MP3s and iTunes Plus AACs without DRM) so that I could use it on my Blackberry Bold cellphone and skip the iPhone. Music and video stream just fine off of it. Class 2 SDHC cards run at minimum 2MB/s and I doubt you'll run into any instances where you won't be able to play media files off it.
Make sure your cell phone device can support 16GB micro SDHC cards before buying, some can't. Most card readers should be able to handle it as it comes with an SD adapter and I had no problem writing to it with my old Sony multi-card reader I got a couple years ago.
That being said, Class 2 is slower than I'd prefer for transferring large files back and forth (for small files like documents you'll hardly notice). If they had a Class 4 16GB available I would have paid a little extra for it, but Class 2 was the only thing available. If you plan on just copying over music once in a while, this shouldn't be much of an issue. But if you are constantly moving video files, it can get annoying.
If I could go back, I'd get a Kingston 8GB Class 4 (4MB/s) micro SDHC for half the price and half the wait, at least until they release a faster 16GB card.