Hello Christopher,

yes it is supported see it is even supported in a C4006

sh module
Mod Slot Ports Module-Type               Model               Sub Status
--- ---- ----- ------------------------- ------------------- --- --------
1   1    2     1000BaseX Supervisor      WS-X4013            no  ok
2   2    48    10/100/1000 Ethernet      WS-X4548-GB-RJ45    no  ok
3   3    48    Inline Power Module       WS-X4148-RJ45V      no  ok
4   4    48    10/100BaseTx Ethernet     WS-X4148-RJ         no  ok
5   5    48    10/100/1000 Ethernet      WS-X4548-GB-RJ45    no  ok
>> 6   6    48    10/100/1000 Ethernet      WS-X4448-GB-RJ45    no  ok

with catos 8.4(11)GLX

and also on C4506

sh module
Chassis Type : WS-C4506

Power consumed by backplane : 0 Watts

Mod Ports Card Type                              Model              Serial No.
---+-----+--------------------------------------+------------------+-----------
1     2  1000BaseX (GBIC) Supervisor(active)    WS-X4013+          JAE081161WP
2    48  10/100/1000BaseT (RJ45)                WS-X4548-GB-RJ45   JAE081169LZ
3    48  10/100/1000BaseT (RJ45)                WS-X4548-GB-RJ45   JAE081169NL
>>> 4    48  1000BaseX SFP                          WS-X4448-GB-SFP    JAB085103MM
5    48  10/100/1000BaseT (RJ45)                WS-X4548-GB-RJ45   JAE08491S7Z
6    48  10/100/1000BaseT (RJ45)                WS-X4548-GB-RJ45   JAE11097GZM

these are two devices in production

Hope to help

Giuseppe