Windows 7 users will have install Service Pack 1 if they want to continue to receive security fixes and other support beyond April 9th.
With the release of a Service Pack, Microsoft's policy is to support the old version for two years. Windows 7 Service Pack 1 was released on 22nd February, 2011, so the phasing out of support is happening more or less on schedule.
In spite of a growing number of post-Service Pack 1 fixes and updates, Microsoft has shown no signs of shipping a second Service Pack. Should Service Pack 1 be the sole major update for Windows 7, it will continue to receive mainstream support—which encompasses both security updates, non-security bugfixes, and free phone support—until 13th January 2015.
Extended support—security fixes and paid incidents only—will continue until 14th January 2020.