Silverado Classic can still be ordered with a Manual.
Ford did this too in 2004, New Body style only available with V8s and no manual transmission. In 2005, the 4.2L V6 carried over.
Its unfortunate. You can still get a F150 with a 5 speed, but only in V6, and XL or STX only.
F250 and up can still be had with a manual trans.