1. Chinks in the champions' armour
Only the final-quarter arrival of the cavalry from the bench swept England past France in an ugly start to their title defence. Despite the 19-16 win setting a new national record of 15 successive victories, vulnerabilities were exposed at Twickenham - inconsistency chief among them. Eddie Jones has taken responsibility for the worst display of his reign and Saturday's opponents Wales will sense weakness.
2. Wales threat to England tough to gauge
Wales posted an emphatic 33-7 victory over Italy in Rome but trailed 7-3 at the break, making hard work of dispatching weak opponents in poor conditions. A final-quarter flurry of tries carried them clear, but there was little here to worry England and it is hard to know what to expect from Rob Howley's men.
3. Scotland on the march
It was not enough to significantly improve their prospects of winning the Six Nations in the eyes of bookmakers - they are fourth favourites - but Scotland's victory over Ireland sent shock waves through the tournament in its opening game. The 27-22 win at Murrayfield could prove to be a coming-of-age performance for Vern Cotter's side, the question now is whether they can sustain it into the latter rounds.
4. Lions selection begins to take shape
Scotland could provide their biggest British and Irish Lions contingent for some time with Stuart Hogg at the top of the order after staking an early claim for the Test full-back jersey. Few Irishmen covered themselves in glory, but Owen Farrell shone for England against France and Elliot Daly's versatility could prove alluring, while there were tentative signs that Sam Warburton and Jonathan Davies could be returning to form.
5. Rampaging Picamoles
World rugby is overflowing with high-calibre number eights and Louis Picamoles is among the very best, a one-man wrecking ball whose strength, footwork and athleticism caused England endless problems at Twickenham. The Frenchman is a clever player and while he is guilty of fading in and out of matches, he is sure to be one of the stars of the tournament.
