Not that's been announced, or to my knowledge, even discussed.
The global friends list is HUGE. Did you really fill yours already?
@Roderick
"Huge" is relative.
Before the last increase, my main account was full, my 2nd account was getting near the limit as over flow for the main account.
Now, I've branched even further. My friends have grown beyond one home server for each Heroes/Villains and is now encompassing many servers. Each circles of friends continues to grow.
I expect that late in the year 2028AD, my list will encompass all known players, past present and future. 
Comic and Hero/Villain Culture
Saturday January 29th, 2005 (12:37 PM) ~ Monday August 9th, 2010
Those Who Lived It Will Remember Long after your Ban Hammer Crumbles and the servers flicker dead.
We Will Remember This One Moment In Time! ~ Shadow Ravenwolf
I have a question. Is there anything in the future of increasing the global friends list limit?