The Ready Reserve Corps actually exists already. If you look at the text it says

Quote Originally Posted by bill
Section 203 of the Public Health Service Act (42 U.S.C. 204) is amended to read as follows:

SEC. 203. COMMISSIONED CORPS AND READY RESERVE CORPS.
Quote Originally Posted by LBJ
When you look at the previous legislation E.O. 11140, it reads:

Executive Order 11140--Delegating certain functions of the President relating to the Public Health Service

Source: The provisions of Executive Order 11140 of Jan. 30, 1964, appear at 29 FR 1637, 3 CFR, 1964-1965 Comp., p. 177, unless otherwise noted.

By virtue of the authority vested in me by Section 201 of Title 3 of the United States Code, and as President of the United States, it is ordered as follows:

Section 1. The Secretary of Health and Human Services is hereby authorized and empowered, without the approval, ratification, or other action of the President, to perform the following-described functions vested in the President under the Public Health Service Act (58 Stat. 682), as amended:
(a) The authority under Section 203 (42 U.S.C. 204) to appoint commissioned officers of the Reserve Corps.
So you see the Ready Reserve has existed in some fashion at least since LBJ. It seems that Obama is just re-structuring it rather than creating an entirely new agency.