With 21 names on a list and 6 lists, we have a total of 126 active names for Atlantic storms. However, out of those 126 names, there are 19 names that have never been used (Van, Wendy, Paulette, Rene, Sally, Teddy, Vicky, Wilfred, Rose, Sam, Teresa, Victor, Wanda, Tobias, Virginie, Walter, Whitney, Valerie and William), not counting retirement replacements who's lists haven't yet been used.

As coastal population and infrastructure increases, the destructive potential of hurricanes also increases, and we can see this trend in the increasing amount of retired names from the 1950's until today. Interestingly, you can also pick out the quieter period of the 70-80s as well.
What this is leading to is a lot of single letters getting retired, the most obvious being I with 11 retired names (Ione, Inez, Iris, Isidore, Isabel, Ivan, Ike, Igor, Irene, Ingrid & Irma). We are now scraping the barrel of familiar names that start with the letter I.
There are a few ways that we could address these potential problems. One is have the lists rotate through all letters over the course of several hurricane seasons. This system is already what's used in the Western Pacific as well as the Central Pacific. Instead of the end-of-alphabet names being used once a decade, they would likely be used at least once every 2-3 seasons. Another could be to have a back up seventh list of names that only gets used when a season passes the end of its regular list; essentially the Greek alphabet equivalent but real names instead.
Something else to consider, however, is that we can probably to retire less of the early-alphabet names and retire more of the later-alphabet names as we detect and name more storms. Both due to increased activity, but also over time due to improving methods of monitoring tropical cyclones (from ship reports in the 1950s to reconnaissance flights in the 1960s, satellite imagery in the 70s, QuikSCAT and ASCAT etc.). Here's a chart showing that as the decades have gone on, we have shifted from retiring more early letters to letters later in the alphabet.
Not really suggesting anything one way or another - just thought this would be a good place to discuss these types of things, especially with what is looking to be another pretty active season ahead of us.