another Comcast head-end goes digital

[Tom Metro]

I received a letter from Comcast today informing me of their plans to 
switch their expanded basic channels from analog to digital-only on 
2/24/10 in Newton. No surprise there. I had already heard from them or 
other sources (I don't remember which) quite a while ago that the 
transition would happen early in 2010.

So two questions:

1. Should I expect most of these digital-only channels to be encrypted? 
This page:
http://www.mythtv.org/wiki/Comcast_Users_And_scte65scan
written in response to the Comcast transition, describes a procedure for 
setting up channel mapping for clear-QAM tuners, implying that such a 
thing is still useful.

2. Anyone currently using a Comcast "Digital adapter" (bare-bones cable 
box) with MythTV? If so, are you using IR or something else to control 
it? If IR, what IR hardware are you using, and how reliable has the 
control been?

The alternative would be renting one of their higher-end cable boxes 
that might provide Firewire control. (I assume the low-end ones don't 
provide that.) I currently have a Motorola DCT2244/1661/ACDEG (which I 
haven't tried using with MythTV). It doesn't provide Firewire (I asked 
for a box that had it when I picked it up, and the people at the Comcast 
office were clueless), but has an IR port and a serial port. I see the 
serial port can be used for control. Does it work better than IR enough 
to justify a $2/month rental for a second tuner?

  -Tom