Yea, let's dogpile on the Vuelta. Sierra Nevada this year was stage 4. You want to tell me you expect a four HC climb stage halfway through week 1? The Lagos de Covadonga stage in 2010 was a stupid stage for sure, but then the Tour does that a lot - Ventoux in 2009 being notable. Hell, in 2010 the Vuelta had a one climb stage to Vallnord Sector Pal - Pal!!! - and it was exciting.
There are plenty of climbs that are long enough and hard enough to create gaps, and big ones at that. Not just Anglirú, but elsewhere. The Coll de Pal is 19km at 6,5%, Vallter2000 as used in the 100%Tondó ride is 19,4km @ 6%, and both can be attached to some gradual but long Catalunya climbs. San Miguel de Áralar is in Navarre and can be attached to a couple of good climbs, though it is likely to have some flat before the base of the final climb, which is 11,2km at 8,1% on the same type of concrete roads as Bola del Mundo. Haza del Lino has several approaches; two from the south are 22,2km @ 5,8% (but with an incredibly tough middle section before a small descent and more gradual finale) and another at 18,0km @ 7,1%, but it has the benefit over many of the other mentioned climbs of being able to be used as a pass and so there can be a wider range of things done with it. Collado Trevinca can be climbed from its Galician side (27,2km @ 5,5%, last 7km @ 8,1%) or from Castilla y León (10,7km @ 7,3%) where it can be attached to the difficult Alto del Peñón. Certainly you could take your cues from the Vuelta a Asturias and go over Pozo de la Mujeres Muertas (11km, 6,2%) as a lead in to a finish on the Alto del Acebo (10km, 8,1%).
A while back I posted this Vuelta tappone from Ponferrada to Oviedo. It's 230km and features a number of major climbs, which become less extreme and shorter as the stage goes on, but with more opportunities for escaping given all of the destruction already in people's legs.
Climbs:
Puerto de Somiedo (17,8km @ 2,7%)
San Lorenzo (10,4km @ 8,4%)
Puerto de la Ventana (18,0km @ 5,9%)
Alto de la Cobertoria (8,8km @ 7,8%)
Alto del Cordal (5,6km @ 8,9%)
Alto de la Vara (7,0km @ 5,7%).
There are a few variations you can try on this - for example, you could leave Ventana out and go straight from San Lorenzo to la Cobertoria; you could ignore la Vara and the run in to Oviedo and instead go up Anglirú after El Cordal, you could continue past Oviedo and add Monte Naranco (5,5km @ 6,5%) as an MTF, you could replace Cordal and La Vara with a Cotobello finish like in 2010, or - my personal favourite - you could replace La Vara with the smaller climb to Ablanedo (5,0km @ 6,4%, but includes a stretch of up to 19%).