Barclays sees several challenges ahead for Vodafone post-Verizon Wireless, not least increasingly tough European mobile trends for the group and how it can make best use of its underleveraged balance sheet. More intriguingly, there is the ongoing press speculation that a bid by AT&T is looming for the UK mobile giant.After considering the potential impact on Vodafone of these challenges, Barclays analyst Maurice Patrick and his team see the balance of risk for the stock skewed to the upside, especially with regards to the AT&T scenario given historical M&A precedents. Patrick notes that Vodafone's European mobile service revenues fell a hefty 7.8% in the third quarter and that the group is underperforming its peers on this front. He anticipates an improvement in underlying trends in 2015, due partly to easier comparatives, but cautions that "fundamentals here remain tough due to challenging macro conditions and competition". Project Spring, Vodafone's ambitious multi-billion pound network investment initiative - much of it aimed at Europe - could help the group not only offer a differentiated product, especially versus smaller rivals, but also enable it to make better use of its under-leveraged balance sheet, according to Patrick. But a bid from AT&T would clearly offer more immediate upside. Barclays currently rates Vodafone at 'overweight? with a price target of 260p. This, however, provides only limited upside on any AT&T bid materialising. A fuller valuation analysis by Patrick applies historical European M&A multiples of 7.2 x EV/EBITDA to Vodafone and suggests a take-out price of around 300p for the group. Broker Oriel Securities has downgraded Tesco after the troubled supermarket chain launched £200m of price cuts and said it was stepping up its store revamp programme.Oriel, which downgraded Tesco from a 'buy' to an 'add' last October, reduced its recommendation again to 'hold' with a 325p target price.It criticised Tesco's plans to speed up its turnaround programme outlined at the group's strategy day on Tuesday, saying they were just "more of the same".Clarke halved capital spending plans to just £700m a year from £1.4m a year and effectively abandoned Tesco's target for a UK operating margin of 5.2%, the highest in the industry, by saying "the margin will be what the margin will be."Clarke said he did not see the need for a change of strategy, saying the group just needed to speed up its turnaround plans.But he admitted the group's performance "has not been what we wanted it to be".He outlined plans to revamp all the company's larger stores by 2017 and to expand in convenience and online retailing, including click-and-collect.Oriel said Tesco needed to do more than it was doing at the moment to overhaul the business, including increasing its planned £200m of price cuts and improving product quality.It said it was taking 5% off its UK pre-tax earnings before interest forecast for Tesco next year, which meant pre-tax profit progress was unlikely.Oriel said: "We disagree with management that a firm base has been rebuilt, and that simply evolving the current strategy will bring results."With the exception of some aggression where online is concerned, there was nothing much of any substance on how Clarke and his team see the brand moving forward."Broker Panmure Gordon is reviewing its forecasts for Taylor Wimpey following "strong" annual results, but said it was keeping a 'hold' recommendation on the house-builder for the time being.Panmure said it was likely to raise its earnings per share forecast on Taylor by between 1% and 3% after Taylor said EPS was 6.7p. Panmure has a 2014 EPS forecast of 9.46p.But the broker said it was set to trim its forecast of net asset value, which for 2013 came in at 69.6p, below Panmure's 73p forecast.Taylor increased annual operating profits by 39 per cent to £312.9m and revenue in the year to December 31st by 13.7% to £2.3bn. It also said it was returning about £250m to shareholders, of which £50m would be in 2014 and £200m in 2015. Panmure said: "We recognise the value being delivered through early payments of cash back to shareholders. For now, we maintain our 112p target price and 'hold' recommendation."AB