As you know, we now have weekly data on vgcharts for 'Others', Japan and the Americas.  I have set up a system below that could make predictions simpler.

I would like to establish weekly benchmarks where we can 'grade' console sales.  This way we can identify the range of sales we expect a console to see for a given time period with a simple letter grade instead of a long explination.

In the USA, to me, selling 50,000 hardware units a week is solid.  I'll call that B-, because not all (relatively successful) consoles do that consistantly in the USA.  We'll also work on the assumption that a console needs all a's and b's to be dominant worldwide...Adjusting for the rest of the Americas, I think 57,500 is a good bench mark as a middle B-.  So i'm going to call 55,000 to 60,000 B- for the Americas (220,000 to 240,000 in sales for the 4 week month). 

F (failing) will be under 20,000 in the Americas

D- will be 20,000-26,500 in the Americas

D will be 26,500-33,500 in the Americas

D+ will be 33,500-40,000 in the Americas

C- will be 40,000-45,000 in the Americas

C will be 45,000-50,000 for the Americas

C+ will be 50,000-55,000 for the Americas 

B- will be 55,000-60,000 for the Americas. 

B will be 60,000-70,000 for the Americas.

B+ will be 70,000-80,000 for the Americas.

A- will be 80,000-90,000 for the Americas.

A will be 90,000-100,000 for the Americas 

A+ will be 100,000+ for the Americas

For perspective, PS2 easily falls into the A+ range, Gamecube falls into the C- range, and Xbox falls into the low or high B range depending on whether or not you count 2006 as a 'supported' year.  I counted up through April 2006 as that is when 360 started gaining alot of momentum in the USA, but I counted GC through April 2007 as it still sells 10k to 30k per month, while Xbox is under 1k per month.  At the moment Wii is in the A+ range and 360 is borderline B+/A-.  PS3 is borderline B-/C+ at the moment.  In terms of change, PS3's grade is dropping, 360 is always B/C range except for holidays (so far), and Wii is slowly rising.

For Japan, there seems to be a split in how well consoles do.  In the USA you have consoles that have sold 1 milliom, 5 million, 10 million, 20 million, and soon 40 million..In Japan you have hardware that sells over 15 million - NES, SNES, PS1, PS2 for instance, or you have hardware that sells under 6 million - Saturn, N64, GC, Genesis, Master System, Xbox.  Establishing thresholds is therefore a bit more difficult.  The PSP however seems to be between the two extremes, and will likely end up around 10 million in Japan, so I will be using it as my B- console.  Assuming the console is supported for between 5-6 years by Sony in Japan, it will sell around 35,000 units each week.  The B- range will be 33,000-37,000 per week then for Japan.

F (failing) range will be under 4,000 per week 

D- range will be 4,000-9,000 

D range will be 9,000-14,000 

D+ range will be 14,000-19,000 

C- range will be 19,000-24,000

C range will be 24,000-29,000 

C+ range will be 29,000-33,000 

B- range will be 33,000-37,000

B range will be 37,000-41,000

B+ range will be 41,000-47,000

A- range will be 47,000-53,000

A range will be 53,000-59,000

A+ range will be 59,000+

For perspective, Xbox failed last generation in Japan.  PS2 got an A+ last generation in Japan.  In between, GC got a D last generation in Japan.  At the moment, Wii is way above the minimum for A+, as PS2 was in it's hayday.  PS3 is in the B-/C+ range but falling rapidly.  360 is out of the failing range at the moment (D-), a significant (if paltry) improvement the original Xbox in Japan.

The real challenge now is to invent European + others benchmarks.  PS2 has shipped 45 million+ in 78 months or so in Europe, so that would imply ~ 130,000/week for over 6.5 years (uh PS2 launched in Others in 2000 right? I forget) is about the limit of the market right now.  My estimate for a B- in Europe/others is 48,000 per week.  So here is how I would set up the ranges.

F (failing) range will be under 11,000 

D- range will be 11,000-16,000 

D range will be 16,000-21,000 

D+ range will be 21,000-26,000 

C- range will be 26,000-31,000 

C range will be 31,000-36,000 

C+ range will be 36,000-44,000 

B-  range will be 44,000-52,000

B range will be 52,000-60,000

B+ range will be 60,000-65,000

A- range will be 65,000-70,000

A range will be 70,000-75,000

A+ range will be 75,000+ 

Last generation PS2 was easily in the A+ range, GC was in the D range, and Xbox was in the C range.  Currently, Wii is just barely in the A+ range, PS3 is well within the A+ range because of the huge launch and strong numbers for the following few weeks - but numbers are dropping quickly.  360 is in currently in the C+ range.

In terms of worldwide grade ranges per week, adding up the three regions gives you this:

A+ range will be 234,000+

A range will be 213,000-234,000

A- range will be 192,000-213,000

B+ range will be 171,000-192,000

B range will be 149,000-171,000

B- range will be 132,000-149,000

C+ range will be 115,000-132,000

C range will be 100,000-115,000

C- range will be 85,000-100,000

D+ range will be 68,500-85,000

D range will be 51,500-68,500

D- range will be 35,000-51,500

F range is under 35,000 per month

For Japan... You say PS3 is in the B-/C+ area... But it's at 8200 units a week... So doesn't that put it in the D- categorie! And looking at the date of the threat opening i'm correct with this statement!

that's a pretty awesome idea mate, hope ioi reads this :D

Sounds good, but I think it primarily depends on the seasons as well. IE, in the Holidays (Nov-Dec), increase these averages and numbers to about 3x the numbers you've given.

It is weekly averages. PS3 right now has D- sales, but it is not anywhere near that low on average.