This is technically hearsay but since I've observed it first-hand hopefully it still counts =)
My mom started eating vegan in mid-January. Within the first month she says she lost her cravings for meat, dairy, cheese etc (which, for my 67-year old mom, is saying a LOT) and two months in she lost 10-12 pounds (now stabilized at her ideal weight), lowered her cholesterol from some crazy high number to 170 (with only 1/4 the amount of statin meds she was previously prescribed), and now has no problem enjoying her veggie meals even when she has to cook meat dishes for company. Her energy is way up, she looks great and she feels so good she is chastising her doctors for not putting her on a vegan diet instead of shooting her up with drugs!
I'm sure the timelines are different for everyone and also depending on what you were eating before, but once you get past the first 30 days of "detox" you should be in great shape!