An insider at Comcast informs Broadband Reports that Comcast users should expect a shake up in the company's speed tiers sometime during the next eight months. The changes should arrive as Comcast continues to push their "Xfinity" rebranding effort into different markets. According to the source, the new Comcast tiers will be 12/2 Mbps, 20/4 Mbps, 50/10 Mbps, and 100/25 Mbps. Current 22/5 customers will be grandfathered, according to the source, and Comcast apparently hopes to get that 100 Mbps tier into about 20% of their footprint this year.

The source notes that these speed tiers could change before final launch.

Comcast's current speeds differ depending on whether you're in a DOCSIS 3.0 upgraded market or not. Non DOCSIS 3.0 market customers currently have the choice of three tiers: 6/1 Mbps, 8/2 Mbps, and 16/2 Mbps. DOCSIS 3.0 upgraded markets have their choice of 12/2 Mbps, 16/2 Mbps, 22/5 Mbps, or 50/10 Mbps. Customers in Minneapolis currently can get a 100 Mbps tier, though that tier will expand into additional markets at a price point that's more reasonable than the $370 charged in Minneapolis.

Much later this year it looks like Comcast users will also start seeing some faster upstream speeds. As we noted last month, upstream DOCSIS 3.0 channel bonding appears to finally be coming together. Comcast says they're now able to deliver a consistent 75 Mbps upstream in field tests, and 100 Mbps upstream in lab tests. Comcast CTO Tony Werner had originally been telling reporters that faster DOCSIS 3.0 speeds would drop during the first quarter of 2010, but all indications are now that an upstream bump for Comcast customers won't occur until late this year.

Update: Says our source: "all signs are pointing that we will still offer the economy tier (1mb/384k) along with all the other tiers listed," for those of your wondering about the possible death of their economy tier.