Acer is hosting a press conference later in the day today, where it is expected to launch its first ultrabook, the Aspire S3. The 13.3mm thin ultrabook reminds us of the MacBook Air and features a 13.3-inch 1366 x 768 pixel display and comes in Intel i3, i5 and i7 configurations. Acer promises 1.5 second instant-on from sleep and 2.5 second instant connect to Wi-Fi. Much on the lines of the MacBook Air, the Aspire S3 can remain in deep sleep for 50 days on a single charge. However, unlike the MacBook Air, the Aspire S3 has all the ports placed at the rear, which includes two USB ports, an HDMI port and a card reader. It does not have an Ethernet port. We will be at the event to bring more details as they come our way. Stay tuned.