Update: Research In Motion has resolved the issue and all messaging services have returned to normalcy.
Research In Motion has confirmed that there is an ongoing outage that is affecting users in the Americas. Around only 6% of all users have been affected by this issue which has prevented many of us (myself included) from doing anything with BBM, and email.
Users will get a check mark when sending a BBM, but will get no delivery or read receipt in return. Sporadically messages will go through as the main backlog is being cleared.
This is the second outage in two days that has affect RIM's services. Yesterday's outage affected the EMEA region for around 3 hours, for which Thorsten Heins would later issue an apology.
RIM's NOC team is on the job right now and they expect the issue to be fixed within the next 2 hours, although if they do encounter complications this could be extended. If you are being affected by this outage, let us know in the comments.