The firm already has a 13.3" XPS M1330 and a 17" XPS M1710 and M1730 and as you've probably already guessed by now the M1530 falls between the M1330 and M1710 with a 15.4" LCD display.
Here's a look at the features:
15.4" LCD display Display resolution: 1680 x 1050 with CCFL, 1440 x 900 with LED backlight Processor: 1.5GHz Intel T5250 up to 2.6GHz T7800 Chipset: Intel Crestline GM/PM 965 Memory: up to 4GB 667MHz DDR2 Graphics: NVIDIA GeForce 8400M or GeForce 8600M GS Blu-ray / 8x DVD±RW drive (slot-loading) WiFi 802.11 a/b/g/n, WWAN and Bluetooth options 2 megapixel webcam (with CCFL display) or 300k (with LED display) HDMI, VGA, FireWire, ExpressCard, three USB 2.0 ports, Ethernet, fingerprint reader and media reader Weight: about 1.8kg (4 pounds) but that's probably without battery