This was pre-announced a few weeks ago, but here is the formal announcement of the new IBM-server based Lotus Foundations offering:
IBM Lotus Foundations Server features server-class quad-core Intel Xeon and Pentium Core 2 Duo processors for performance and stability
Features of the IBM Lotus Foundations Server include:
  * Intel Core 2 Duo E7200 2.53 GHz or Xeon X3330 2.66 GHz quad-core processors
  * Standard system memory consisting of 2 GB or 4 GB PC2-6400 CL6 ECC DDR2 800 MHz DIMMs; 8 GB1 maximum
  * Integrated Serial-ATA (SATA) controller
  * 5.25 inch removable backup drive kit with 500 GB or 1 TB simple swap SATA HDD (model dependent)
  * LCD monitor display
  * Flash drive for intelligent data backup and recovery
  * Five available I/O expansion slots
  * System management support
  * I/O ports:
     o Six USB (four rear, two front)
     o Three Ethernet ports:
        + Integrated Gigabit Ethernet with RJ-45
        + Dual-port Ethernet adapter
     o Two software-compatible serial ports
     o One parallel port supporting devices using SSP, EPP, or ECP protocols adhering to the IEEE 1284 standard
  * Integrated ATI graphics controller with 16 MB video memory and one rear port
Available on December 5th, these new servers look to be a big step forward in scalability and performance from the older Nitix style systems.
Links to Announcement Letter in HTML and PDF.