Following up on Sunday's "San Andreas PC Exclusively on DVD?" news, I made some calls and it turns out San Andreas PC will indeed by shipping on a DVD. A kind bloke at Take 2 tech support with a UK accent confirmed that because the game is so large, it will be shipped on either a dual layer DVD disc (DVD-9) or perhaps a single layer DVD disc (DVD-5). He also let me know that the system requirements will be released closer to release date.
So while on Sunday there was still a possiblity that those without DVD readers will be able to play San Andreas on PC, that hope has been lost and come June you will have to cash out for a DVD reader.
This new information has been mirrored at the San Andreas PC and Xbox information page.