DVB-S/S2 PCIe card from DVBSKy
- Dual/Twin Tuner input
- PCIe x1
- Low power
- External Power by PCI Express 6-Position Power Connector
- RF: Montage M88TS2020
- Demodulator: 2nd generation Montage M88DS3103
- PCIe Bridge: Conexant CX23885
Officially here, with firmware : http://www.dvbsky.net/Support.html
You have an howto in french here for debian : http://wiki.debian-facile.org/manuel:installation:dvb:dvbs2:dvbsky
and an active mailling list from a reseller here : http://www.dvbshop24.com/index.php/topic,9513.90.html
For users preferring minimally-intrusive kernel tree patching + recompile over installing separate V4L (as second approach is potentially risk if You have other tuners in system which are not covered by media build V4L instance) here are patches for 3.3.x & 3.5.x kernels 
The driver seems to have some configuration issues: http://code.mythtv.org/trac/ticket/10830
Also reported problem with openelec
The card needs a power supply other than the one provided by the PCIe, so there is a plug on the card. It can not work if not connected.
If configured properly, card works really well under MythTV 0.25.2 & Unicable.