So, I do not know why the T5670 isn't on the table, but here is where you can find more information:
We designed ARK to be quick and easy to use - just put the T5670 (or any processor number) into the search box (the one below the banner, not at the top), and you should get your answer, if the product has been launched.
However, having said that, the T5670 is not recommended for embedded designs, because does not support the longer life cycles (7+ years) that the embedded market usually requires. That being said, here are similar (all based on the same fundamental die) that do have the longer manufacturer availability usually needed:
If you have any questions, we have a support email that can help: ARK_Support@intel.com
Thanks for considering Embedded Intel® Processors