I apologize if this is common knowledge and/or this topic has already been extensively discussed; I did a quick topic search for CLI and didn't see anything recent.
I remember the glory days when AMEX gave out CLIs online like candy. I had all my cards increased, and life was good. After the crash and crunch, AMEX rolled back my limits significantly. I remember frequently checking the account options online and the "Request CLI increase" button was not there (if I recall correctly).
Today, I logged back in to try to find the phone number to request a CLI manually. Lo and behold, harkening back to the glory days, the button was back. For fear of getting the "We'll mail you in 5 days with the results", I requested a modest increase (less than 2x my current limit). I was auto-approved. Is this new news or old news??
I hope this helps somebody..if not, mods feel free to delete.
Bump with an update:
The option to reallocate among 2 cards is now there too; it's just kind of buried. After logging in to your Summary of Accounts, click on "Recent Activity" for any card. At the bottom, there is an option for "Transfer Available Credit to Another Card".