Why can't you see what you downloaded today for attachments? I upgraded to Mail 6.2 and noticed they appeared to do away with the "Today" option when I am searching to place an attachment with an email?

Is there something I have to check to make this appear again?
This is still possible. When composing a new email, after clicking the "Attach" icon in the upper right corner, select "All my Files". This will show you a list of all you recent files.

You can change even this view somewhat by changing the display configuration icons in the upper right corner of the attachment window. There are 4 options including: thumbnail view (which sorts files by type), and list view (which makes it easy to see meta information on the files, as well as two other views.