Is there any advantage to one blood type over another?
I've been doing a little more digging myself and have found a couple of other advantages:

Risk of Venous-thromboembolism (deep vein thrombosis/pulmonary embolism (1)).  Blood group O individuals are at lower risk of the above conditions due to reduced levels of von Willebrand factor(2) and factor VIII clotting factors.

Cholera Infection Susceptibility &amp; Severity.  Individuals with blood group O are less susceptible to some strains of cholera (O1) but are more likely to suffer severe effects from the disease if infected (3).

E. coli Infection Susceptibility &amp; Severity. A study in Scotland indicated that those with the O blood group showed higher than expected infection rates with E. coli O157 and significantly higher fatality rates (78.5% of fatalities had blood group O).(4)

Peptic Ulcers caused by Heliobacter pylori which can also lead to gastric cancer.  Group O are again more susceptible to strains of H. pylori (5).

Whether blood group antigens are displayed on other body cells or not has been linked to increased or decreased susceptibility to many diseases, notably norrovirus and HIV.  This is fully explained in the article that I was above summarising - "The relationship between blood group and disease" in addition to extended descriptions of the other two answers.