If you see what was happening prior to these Test series, T-20 was freely being played and it was an overdose of T-20, which culminated with the ICC W.C. triumph for West Indies.
Suddenly all the teams have started playing Tests, so from T-20 overdose to all the countries playing Test series, another drastic change has taken place.
Now to measure Test cricket's health on these grounds, is tough & figures are inflated for sure.
People know that an ODI will take about 8-9 hours of their time, maybe 10 at the most.
T-20 takes not more than 4-5 hours, with crack cricket being played thoroughly, in those 40 overs of every game. Hence they have their own following, which is looking on the increase.
Tests are a cricketer's ultimate exams, where they appear to ascertain their quality, not the quantity, which is engaged in ODI's & T-20. Tests separate men from boys.
So quality against the quantity, means that Tests have limited no. of followers, who appreciate the game in toto. Its tough but Tests are not dying but lagging behind both T-20 & ODI's due to their limited nature. So true cricketers & its true fans would help keep Tests alive, ALWAYS..
No, T-20 aren't killing Tests but they are infecting youngsters with instant cricket, which they will believe is real cricket in the future, which would be sad..