The 360 has sold 11.6M consoles in america far outselling sony's relatively piddly 4.94M in america.  In fact they have sold 2.34X's  Sony's #'s for american console sales.  Well, even so, they recently sold only 1.6X's as many software titles.  So, the 360 seems to really be lagging behind what it should be doing.  Comments for my 5 cent analyssis?

As userbase expands, software sales won't keep up proportionally with newer systems of a smaller userbase. This is to be expected, really. As the 360 ages, some consoles will be put out of use, left to collect dust, or ignored for newer toys in peoples' houses. Sooner or later, it will happen to the PS3 and Wii as well.

uh, no, it should expand rocket pig. Most people just need one console and then get multiple games for it over time, but the 360's sales really aren't that great. Granted this is only a superficial analysis b/c MS will probably sell 5 or 6X's the amount of DLC type of games than the PS3 on any given week, but hey, Sony seems to be catching up, w/ this Qore thing, HOME which will come in another 3 years, and the online chatting thing and universal friends that sony has.  I think that the PSN is improving so its sales will improve as well.

I just really think that this, and other stats are starting to show that the 360 wasn't the juggernaut that we thought that it was just a year ago.

Okay, maybe I'm not understanding your OP. Are you talking about all-time software sales or week-by-week software sales?

All-time should be higher, week-by-week should be proportionally lower. 

But was 360 "Ever" thought as a juggernaut apart from HUGE M$ fanboys....as it really never was

 are you trying to say that as the weeks go by, the amount of proportional sales would be lower and lower? Well, I guess, according to you anyway.

I think data for some of the first 360 games are missing.

Attach-ratio wise, the 360 has been a juggernaut at points of its life.  I don't know how the overall picture looks now, but in general it's one of the highest attach rate consoles ever.

Compared to newer systems, yes. If the PS3 is one year old and sells 5m units and the 360 is two years old and sells 10m units, week-by-week software sales should technically be 1:2 in favor of the 360 (given complete neutrality in game releases). The problem is that they're not. Since the 360 is one year older, there is a higher likelyhood that some people aren't using their system anymore, they have broken and are not repaired, or people just lost interest and moved on to other things (including, possibly, the PS3).

After all, I don't see the PS2 moving over 10 times more softare than the 360... Which it should given install base.

 I thought that it was a pretty big thing for a while.  I was really impressed with all that they have done for the online stuff.  But even so, they are falling behind week by week hardwardware, and eventually if the current trend continues they will fall behind in software, as well.  Have you ever seen Muhammad Ali's early fights?  He wasn't the greatest, not by a longshot.  But then, he improved his footwork and evasiveness, he worked on his power as well.  All of these things added up to him eventually being the best and on a similar note, the PS3 will be improving its game by a large amount this year w/ the following:

-increased blu ray sales

-HOme

-in game messaging/ universal friends

-Qore

 -PlayTV

-Rumble

For real, assuming that these come out this year, then sony will have done much much more than the other two and  there is the talk of a price cut by the end of the year as well