Analysts are weighing in today on IT services issue Computer Sciences Corporation (CSC - 25.96), battery specialist A123 Systems, Inc. (AONE - 2.95), burrito chain Chipotle Mexican Grill, Inc. (CMG - 330.39), data storage concern STEC, Inc. (STEC - 10.09), and alternative energy company Suntech Power Holdings Co., Ltd. (STP - 2.60). Here's a quick roundup of today's upgrades and downgrades of note.

• After slashing its full-year forecast on Wednesday, CSC has attracted a number of bearish brokerage notes today. J.P. Morgan kicked things off by downgrading the stock to "underweight" from "neutral," and lowering its price target to $27 from $31. BMO Capital chimed in with a price-target cut to $29 from $32, while Barclays lowered its target to $26 from $35. The stock is down about 7% at last check, deepening its year-to-date deficit of 43.8%.
• As for AONE, the equity has shed 4.5% following a pair of post-earnings downgrades. ThinkEquity cut its rating to "sell" from "hold," while Craig-Hallum slashed its recommendation to "hold" from "buy" -- just one day after AONE confessed to a wider-than-anticipated third-quarter loss. After checking out the longer-term price trend, the stock was probably overdue for a few negative analyst notes. Despite AONE's decline of nearly 68% in 2011, Zacks indicates that eight out of 12 analysts still deemed the shares worthy of a "buy" or better rating.
• CMG is down about 0.8% at last look, as traders seem relatively unimpressed by an upgrade to "hold" from "sell" at Miller Tabak. Since tagging a new record high of $347.94 at the end of October, CMG has been consolidating its gains -- but the shares remain comfortably north of support at their ascending 10-week moving average, which has helped to guide CMG about 56% higher in 2011.
• After swallowing a 12.3% loss on Wednesday, STEC has given up another 1.7% today. On the heels of STEC's lackluster fourth-quarter forecast, the stock still managed to score a new "buy" rating from Lazard this morning -- but traders seem less than eager to follow this advice. It's an incredibly rare bullish note for STEC, which is down about 42% for the calendar year. Zacks reports that the other nine analysts tracking the stock maintain skeptical "hold" or "sell" ratings.
• In the wake of Wednesday's mixed guidance, the shares of STP were hit with a price-target cut to $2.50 from $3 at Jefferies. However, the stock is unchanged at last check, with STP clinging to newfound support at its 20-day moving average. This trendline has held the shares aloft since Oct. 26, although STP continues to stare down familiar resistance at its looming 10-week moving average.