The point is not the magic blood... it is the whole setup.
Why do they need to capture Khan to get that blood sample, if they have 72 (!!! ) other augements waiting ON BOARD there.
Plus... this magic blood leads to something, they have created with that transwarp transporter.
Essentially you do not need starships in this reality anymore. Every single person, who watches the movie (as is capable of logical thinking) will ask him/herself the essential question: why didn't Starfleet use the transwarp transporter to follow Khan to Kronos?
The same problem occurs when you think the return from the dead through to the end: You now have the magic blood... death is history.
So, in essence TREK 3 doesn't need starships, nor doctors. The heroes cannot die anymore. That's loss of impact, loss of drama, although I am sure, that Orci and Kurtzman will simply forget that ridiculous plotpoint in the sequel.
Just lay back and enjoy the SFX, action ride, and do not pay to close attention to logic.
New TREK is like TRANSFORMERS and G.I. JOE. Simple, absolutely dumb, loud entertainment which is in essence about nothing but nice visuals and SFX.
Enjoy it as such, or leave it alone.