Mods/admins/people with title editing power: can one of you sync up the title of the thread with what I edited it to, to make it more clear to the uninitiated what this thread is about? Feel free to delete this note at that point
Name: T-Mobile G1, production name HTC Dream.
Why I should care:  First phone running Android OS, and it's preordering in two weeks!
Pics, completely with Terrible Whitebalance, are attached!
Specs list so far, courtesy of Androidguys.com:
Hardware:
Launch Colors: White, Black, Brown
# 528Mhz Qualcomm 7201 processor
# Data kit for USB connectivity in the box
# 128MB Internal RAM 
# 256MB Internal ROM 
[rumored...older rumor had half these values (64RAM/128ROM)]
# 1GB MicroSD card [external slot speculated]
# 5 Row QWERTY keypad
# Trackball
# Dedicated camera button
# 3.1MP camera (no flash) 2048 x 1536
# Bluetooth (class 1)
# SMS and MMS support
# Quad Band (850, 900, 1800, 1900)
# 3G
# aGPS
# Built-in compass
# 802.11b & 802.11g
# UMTS (1,4), HSDPA, SUPL
# 1150mAh battery
# Screen size is 3.17″ with HVGA (480 x 320)
# Handset 117 x 55 x 16mm
# 5.6 oz weight
Software
# Picture Caller ID
# POP, IMAP, and SMTP, AOL, and GMAIL email
# AIM, MSN, YAHOO, and GTALK messaging
# Sync capable with Google Calendar
# Downloadable content via Android Marketplace
# Google Streetview with built-in compass
# Video playback files - H.264, streaming, 3GPP, MPEG4, and Codec 3GP
# Dedicated YouTube Player
# Audio playback files - MP3, AAC, AAC+, WMA, MPEG4, WAV, MIDI, REAL AUDIO, OGG
# Wallpaper supports JPG, BMP, PNG, and GIF
# Speakerphone (mono, natch)
# Ringtones (MP3, AAC, AAC+, WMA)
# HTTP, WAP Push, xHTML
Pricing:
Invoice Price: $399 
New customer price: $200 + $35 activation fee (2-year agreement, no mail-in rebates to mess with) 
Full discount for upgrades: $200 + $18 standard upgrade fee 
Partial upgrade cost: $350 + $18 standard upgrade fee 
Pre-Sale upgrade for full discount: $150 + $18 UF 
Pre-Sale upgrade for partial discount: $300 + $18 UF 
PreSale: September 17th
Actual sale: October
Current Availability Rumor:
Phone will be available for presale on mytmobile website to existing T-mobile customers for one week starting September 17th *(also rumored, although older, as the 13th).  Presale will ONLY be available to customers located in 3G markets.  Rumors conflict as to whether that means cities that currently have 3G (there are only four or five) or those getting 3G roll-out on October 1st, which is this list:
Atlanta 
Austin 
Birmingham 
Chicago 
Dallas 
Denver 
Detroit 
Houston 
Kansas City 
Los Angeles 
Las Vegas 
Minneapolis 
Miami 
Memphis 
New England 
New Jersey & Long Island 
New York City
Orlando 
Phoenix 
Portland 
Philadelphia 
San Francisco 
Sacramento 
San Diego 
Seattle 
Tampa 
Washington DC 
The two presale prices reflect whether or not your contract is up and you are ready for a handset upgrade or not.  There are mixed reports as to how long you must have had a t-mobile contract to be eligible for upgrade.
Once the phones go on sale in October, anyone in any market should be able to purchase them at the prices listed above, dependant on whether they are new customers or eligible for upgrades.
More info in this thread as I collect it...
Main sources:
TmoNews
AndroidGuys